<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="UTF-8">
<meta name="viewport" content="width=device-width">
<meta name="theme-color" content="#222"><meta name="generator" content="Hexo 7.3.0">

  <link rel="apple-touch-icon" sizes="180x180" href="/images/apple-touch-icon-next.png">
  <link rel="icon" type="image/png" sizes="32x32" href="/images/favicon-32x32.ico">
  <link rel="icon" type="image/png" sizes="16x16" href="/images/favicon-16x16.ico">
  <link rel="mask-icon" href="/images/logo.svg" color="#222">

<link rel="stylesheet" href="/css/main.css">



<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css" integrity="sha256-wiz7ZSCn/btzhjKDQBms9Hx4sSeUYsDrTLg7roPstac=" crossorigin="anonymous">
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.1.1/animate.min.css" integrity="sha256-PR7ttpcvz8qrF57fur/yAx1qXMFJeJFiA6pSzWi0OIE=" crossorigin="anonymous">
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/fancyapps-ui/5.0.28/fancybox/fancybox.css" integrity="sha256-6cQIC71/iBIYXFK+0RHAvwmjwWzkWd+r7v/BX3/vZDc=" crossorigin="anonymous">
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/pace/1.2.4/themes/green/pace-theme-minimal.css">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/pace/1.2.4/pace.min.js" integrity="sha256-gqd7YTjg/BtfqWSwsJOvndl0Bxc8gFImLEkXQT8+qj0=" crossorigin="anonymous"></script>

<script class="next-config" data-name="main" type="application/json">{"hostname":"sumumm.github.io","root":"/","images":"/images","scheme":"Gemini","darkmode":false,"version":"8.19.2","exturl":false,"sidebar":{"position":"left","display":"post","padding":18,"offset":12},"copycode":{"enable":true,"style":"mac"},"fold":{"enable":true,"height":300},"bookmark":{"enable":false,"color":"#222","save":"auto"},"mediumzoom":false,"lazyload":true,"pangu":false,"comments":{"style":"tabs","active":null,"storage":true,"lazyload":false,"nav":null},"stickytabs":false,"motion":{"enable":true,"async":true,"transition":{"menu_item":"fadeInDown","post_block":"fadeIn","post_header":"fadeInDown","post_body":"fadeInDown","coll_header":"fadeInLeft","sidebar":"fadeInUp"}},"i18n":{"placeholder":"搜索...","empty":"没有找到任何搜索结果：${query}","hits_time":"找到 ${hits} 个搜索结果（用时 ${time} 毫秒）","hits":"找到 ${hits} 个搜索结果"},"path":"/search.xml","localsearch":{"enable":true,"trigger":"auto","top_n_per_article":1,"unescape":false,"preload":false}}</script><script src="/js/config.js"></script>

    <meta name="description" content="本文主要是uboot——uboot编译时间与版本信息的相关笔记，若笔记中有错误或者不合适的地方，欢迎批评指正😃。">
<meta property="og:type" content="article">
<meta property="og:title" content="LV05-02-U-Boot-07-uboot编译时间与版本">
<meta property="og:url" content="https://sumumm.github.io/post/f68c951e.html">
<meta property="og:site_name" content="苏木">
<meta property="og:description" content="本文主要是uboot——uboot编译时间与版本信息的相关笔记，若笔记中有错误或者不合适的地方，欢迎批评指正😃。">
<meta property="og:locale" content="zh_CN">
<meta property="og:image" content="https://fanhua-picture.oss-cn-hangzhou.aliyuncs.com/01%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/LV05-02-U-Boot-07-uboot%E7%BC%96%E8%AF%91%E6%97%B6%E9%97%B4%E4%B8%8E%E7%89%88%E6%9C%AC/img/image-20241122215559817.png">
<meta property="og:image" content="https://fanhua-picture.oss-cn-hangzhou.aliyuncs.com/01%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/LV05-02-U-Boot-07-uboot%E7%BC%96%E8%AF%91%E6%97%B6%E9%97%B4%E4%B8%8E%E7%89%88%E6%9C%AC/img/image-20241122230044913.png">
<meta property="article:published_time" content="2024-11-24T10:12:17.000Z">
<meta property="article:modified_time" content="2025-06-13T16:25:57.044Z">
<meta property="article:author" content="苏木">
<meta property="article:tag" content="LV05-系统镜像">
<meta name="twitter:card" content="summary">
<meta name="twitter:image" content="https://fanhua-picture.oss-cn-hangzhou.aliyuncs.com/01%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/LV05-02-U-Boot-07-uboot%E7%BC%96%E8%AF%91%E6%97%B6%E9%97%B4%E4%B8%8E%E7%89%88%E6%9C%AC/img/image-20241122215559817.png">


<link rel="canonical" href="https://sumumm.github.io/post/f68c951e.html">



<script class="next-config" data-name="page" type="application/json">{"sidebar":"","isHome":false,"isPost":true,"lang":"zh-CN","comments":"","permalink":"https://sumumm.github.io/post/f68c951e.html","path":"post/f68c951e.html","title":"LV05-02-U-Boot-07-uboot编译时间与版本"}</script>

<script class="next-config" data-name="calendar" type="application/json">""</script>
<title>LV05-02-U-Boot-07-uboot编译时间与版本 | 苏木</title>
  








    <script src="/js/browser_tools_disable.js"></script>

  <noscript>
    <link rel="stylesheet" href="/css/noscript.css">
  </noscript>
<!-- hexo injector head_end start --><link rel="stylesheet" href="https://unpkg.com/hexo-next-tags-plus@latest/lib/tag_plus.css" media="defer" onload="this.media='all'"><!-- hexo injector head_end end --></head>

<body itemscope itemtype="http://schema.org/WebPage" class="use-motion">
  <div class="headband"></div>

  <main class="main">
    <div class="column">
      <header class="header" itemscope itemtype="http://schema.org/WPHeader"><div class="site-brand-container">
  <div class="site-nav-toggle">
    <div class="toggle" aria-label="切换导航栏" role="button">
        <span class="toggle-line"></span>
        <span class="toggle-line"></span>
        <span class="toggle-line"></span>
    </div>
  </div>

  <div class="site-meta">

    <a href="/" class="brand" rel="start">
      <i class="logo-line"></i>
      <p class="site-title">苏木</p>
      <i class="logo-line"></i>
    </a>
      <p class="site-subtitle" itemprop="description">我的学习之路</p>
  </div>

  <div class="site-nav-right">
    <div class="toggle popup-trigger" aria-label="搜索" role="button">
        <i class="fa fa-search fa-fw fa-lg"></i>
    </div>
  </div>
</div>



<nav class="site-nav">
  <ul class="main-menu menu"><li class="menu-item menu-item-home"><a href="/" rel="section"><i class="fa fa-home fa-fw"></i>苏木的家</a></li><li class="menu-item menu-item-categories"><a href="/categories/" rel="section"><i class="fa fa-th fa-fw"></i>分类页<span class="badge">42</span></a></li><li class="menu-item menu-item-archives"><a href="/archives/" rel="section"><i class="fa fa-archive fa-fw"></i>归档页<span class="badge">673</span></a></li><li class="menu-item menu-item-flink"><a href="/flink/" rel="section"><i class="fa fa-link fa-fw"></i>友人帐</a></li><li class="menu-item menu-item-about"><a href="/about/" rel="section"><i class="fa fa-user fa-fw"></i>关于我</a></li>
      <li class="menu-item menu-item-search">
        <a role="button" class="popup-trigger"><i class="fa fa-search fa-fw"></i>搜索
        </a>
      </li>
  </ul>
</nav>



  <div class="search-pop-overlay">
    <div class="popup search-popup"><div class="search-header">
  <span class="search-icon">
    <i class="fa fa-search"></i>
  </span>
  <div class="search-input-container">
    <input autocomplete="off" autocapitalize="off" maxlength="80"
           placeholder="搜索..." spellcheck="false"
           type="search" class="search-input">
  </div>
  <span class="popup-btn-close" role="button">
    <i class="fa fa-times-circle"></i>
  </span>
</div>
<div class="search-result-container no-result">
  <div class="search-result-icon">
    <i class="fa fa-spinner fa-pulse fa-5x"></i>
  </div>
</div>

    </div>
  </div>

</header>
        
  
  <aside class="sidebar">

    <div class="sidebar-inner sidebar-nav-active sidebar-toc-active">
      <ul class="sidebar-nav">
        <li class="sidebar-nav-toc">
          文章目录
        </li>
        <li class="sidebar-nav-overview">
          站点概览
        </li>
      </ul>

      <div class="sidebar-panel-container">
        <!--noindex-->
        <div class="post-toc-wrap sidebar-panel">
            <div class="post-toc animated"><ol class="nav"><li class="nav-item nav-level-1"><a class="nav-link" href="#%E4%B8%80%E3%80%81%E4%B8%BA%E4%BB%80%E4%B9%88%EF%BC%9F"><span class="nav-text">一、为什么？</span></a></li><li class="nav-item nav-level-1"><a class="nav-link" href="#%E4%BA%8C%E3%80%81timestamp"><span class="nav-text">二、timestamp</span></a><ol class="nav-child"><li class="nav-item nav-level-2"><a class="nav-link" href="#1-%E7%BC%96%E8%AF%91%E4%BF%A1%E6%81%AF"><span class="nav-text">1. 编译信息</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#2-timestamp-h"><span class="nav-text">2. timestamp_h</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#3-filechk"><span class="nav-text">3. filechk</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#3-1-Makefile%E4%B8%AD%E7%9A%84%E8%87%AA%E5%AE%9A%E4%B9%89%E5%87%BD%E6%95%B0"><span class="nav-text">3.1 Makefile中的自定义函数</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-2-filechk"><span class="nav-text">3.2 filechk</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-3-%E5%8F%98%E9%87%8F%E7%9A%84%E5%80%BC"><span class="nav-text">3.3 变量的值</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-4-filehck%E5%B1%95%E5%BC%80"><span class="nav-text">3.4 filehck展开</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-5-filechk-1"><span class="nav-text">3.5 filechk_$(1)</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-6-timestamp-autogenerated-h"><span class="nav-text">3.6 timestamp_autogenerated.h</span></a></li></ol></li><li class="nav-item nav-level-2"><a class="nav-link" href="#4-%E8%A7%84%E5%88%99%E5%B1%95%E5%BC%80"><span class="nav-text">4. 规则展开</span></a></li></ol></li><li class="nav-item nav-level-1"><a class="nav-link" href="#%E4%B8%89%E3%80%81version"><span class="nav-text">三、version</span></a><ol class="nav-child"><li class="nav-item nav-level-2"><a class="nav-link" href="#1-%E7%BC%96%E8%AF%91%E4%BF%A1%E6%81%AF-1"><span class="nav-text">1. 编译信息</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#2-version-h"><span class="nav-text">2. version_h</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#3-filechk-1"><span class="nav-text">3. filechk</span></a><ol class="nav-child"><li class="nav-item nav-level-3"><a class="nav-link" href="#3-1-%E5%8F%98%E9%87%8F%E7%9A%84%E5%80%BC"><span class="nav-text">3.1 变量的值</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-2-filehck%E5%B1%95%E5%BC%80"><span class="nav-text">3.2 filehck展开</span></a></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-3-filechk-1"><span class="nav-text">3.3 filechk_$(1)</span></a><ol class="nav-child"><li class="nav-item nav-level-4"><a class="nav-link" href="#3-3-1-filechk-version-h"><span class="nav-text">3.3.1 filechk_version.h</span></a></li><li class="nav-item nav-level-4"><a class="nav-link" href="#3-3-2-UBOOTRELEASE"><span class="nav-text">3.3.2 UBOOTRELEASE</span></a></li></ol></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-4-uboot-release"><span class="nav-text">3.4 uboot.release</span></a><ol class="nav-child"><li class="nav-item nav-level-4"><a class="nav-link" href="#3-4-1-uboot-release%E8%A7%84%E5%88%99"><span class="nav-text">3.4.1 uboot.release规则</span></a></li><li class="nav-item nav-level-4"><a class="nav-link" href="#3-4-3-filechk%E5%B1%95%E5%BC%80"><span class="nav-text">3.4.3 filechk展开</span></a></li><li class="nav-item nav-level-4"><a class="nav-link" href="#3-4-2-filechk-1"><span class="nav-text">3.4.2 filechk_$(1)</span></a></li></ol></li><li class="nav-item nav-level-3"><a class="nav-link" href="#3-5-setlocalversion"><span class="nav-text">3.5 setlocalversion</span></a></li></ol></li><li class="nav-item nav-level-2"><a class="nav-link" href="#4-%E7%94%9F%E6%88%90git%E7%89%88%E6%9C%AC%E5%8F%B7"><span class="nav-text">4. 生成git版本号</span></a></li></ol></li><li class="nav-item nav-level-1"><a class="nav-link" href="#%E5%9B%9B%E3%80%81%E5%BA%94%E7%94%A8%E5%AE%9E%E4%BE%8B"><span class="nav-text">四、应用实例</span></a><ol class="nav-child"><li class="nav-item nav-level-2"><a class="nav-link" href="#1-Kbuild-include"><span class="nav-text">1. Kbuild.include</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#2-Makefile"><span class="nav-text">2. Makefile</span></a></li><li class="nav-item nav-level-2"><a class="nav-link" href="#3-printk-prj-info-c"><span class="nav-text">3. printk_prj_info.c</span></a></li></ol></li></ol></div>
        </div>
        <!--/noindex-->

        <div class="site-overview-wrap sidebar-panel">
          <div class="site-author animated" itemprop="author" itemscope itemtype="http://schema.org/Person">
    <img class="site-author-image" itemprop="image" alt="苏木"
      src="/images/avatar.jpg">
  <p class="site-author-name" itemprop="name">苏木</p>
  <div class="site-description" itemprop="description">莫道桑榆晚，为霞尚满天</div>
</div>
<div class="site-state-wrap animated">
  <nav class="site-state">
      <div class="site-state-item site-state-posts">
        <a href="/archives/">
          <span class="site-state-item-count">673</span>
          <span class="site-state-item-name">日志</span>
        </a>
      </div>
      <div class="site-state-item site-state-categories">
          <a href="/categories/">
        <span class="site-state-item-count">42</span>
        <span class="site-state-item-name">分类</span></a>
      </div>
      <div class="site-state-item site-state-tags">
        <span class="site-state-item-count">43</span>
        <span class="site-state-item-name">标签</span>
      </div>
  </nav>
</div>
  <div class="links-of-author animated">
      <span class="links-of-author-item">
        <a href="https://github.com/sumumm" title="GitHub → https:&#x2F;&#x2F;github.com&#x2F;sumumm" rel="noopener me" target="_blank"><i class="fab fa-github fa-fw"></i>GitHub</a>
      </span>
  </div>

        </div>
      </div>
    </div>

    
  </aside>


    </div>

    <div class="main-inner post posts-expand">


  


<div class="post-block">
  
  

  <article itemscope itemtype="http://schema.org/Article" class="post-content" lang="zh-CN">
    <link itemprop="mainEntityOfPage" href="https://sumumm.github.io/post/f68c951e.html">

    <span hidden itemprop="author" itemscope itemtype="http://schema.org/Person">
      <meta itemprop="image" content="/images/avatar.jpg">
      <meta itemprop="name" content="苏木">
    </span>

    <span hidden itemprop="publisher" itemscope itemtype="http://schema.org/Organization">
      <meta itemprop="name" content="苏木">
      <meta itemprop="description" content="莫道桑榆晚，为霞尚满天">
    </span>

    <span hidden itemprop="post" itemscope itemtype="http://schema.org/CreativeWork">
      <meta itemprop="name" content="LV05-02-U-Boot-07-uboot编译时间与版本 | 苏木">
      <meta itemprop="description" content="">
    </span>
      <header class="post-header">
        <h1 class="post-title" itemprop="name headline">
          LV05-02-U-Boot-07-uboot编译时间与版本
        </h1>

        <div class="post-meta-container">
          <div class="post-meta">
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-calendar"></i>
      </span>
      <span class="post-meta-item-text">发表于</span>

      <time title="创建时间：2024-11-24 18:12:17" itemprop="dateCreated datePublished" datetime="2024-11-24T18:12:17+08:00">2024-11-24</time>
    </span>
    <span class="post-meta-item">
      <span class="post-meta-item-icon">
        <i class="far fa-folder"></i>
      </span>
      <span class="post-meta-item-text">分类于</span>
        <span itemprop="about" itemscope itemtype="http://schema.org/Thing">
          <a href="/categories/%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/" itemprop="url" rel="index"><span itemprop="name">嵌入式开发</span></a>
        </span>
          ，
        <span itemprop="about" itemscope itemtype="http://schema.org/Thing">
          <a href="/categories/%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/" itemprop="url" rel="index"><span itemprop="name">02IMX6ULL平台</span></a>
        </span>
          ，
        <span itemprop="about" itemscope itemtype="http://schema.org/Thing">
          <a href="/categories/%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/" itemprop="url" rel="index"><span itemprop="name">LV05-系统镜像</span></a>
        </span>
    </span>

  
    <span class="post-meta-break"></span>
    <span class="post-meta-item" title="本文字数">
      <span class="post-meta-item-icon">
        <i class="far fa-file-word"></i>
      </span>
      <span class="post-meta-item-text">本文字数：</span>
      <span>8.2k</span>
    </span>
    <span class="post-meta-item" title="阅读时长">
      <span class="post-meta-item-icon">
        <i class="far fa-clock"></i>
      </span>
      <span class="post-meta-item-text">阅读时长 &asymp;</span>
      <span>30 分钟</span>
    </span>
</div>

        </div>
      </header>

    
    
    
    <div class="post-body" itemprop="articleBody"><p>本文主要是uboot——uboot编译时间与版本信息的相关笔记，若笔记中有错误或者不合适的地方，欢迎批评指正😃。</p>
<span id="more"></span>

<!-- Photo: https://fanhua-picture.oss-cn-hangzhou.aliyuncs.com/01%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/LV05-02-U-Boot-07-uboot%E7%BC%96%E8%AF%91%E6%97%B6%E9%97%B4%E4%B8%8E%E7%89%88%E6%9C%AC/img/ -->

<details class="folding-tag" blue><summary> 点击查看使用工具及版本 </summary>
              <div class='content'>
              <table>    <tr>        <td align="center" rowspan="5">PC端开发环境</td>        <td align="center" width=150px>Windows</td>        <td align="left">Windows11</td>    </tr>    <tr>        <td align="center">Ubuntu</td>        <td align="left">Ubuntu20.04.2的64位版本</td>      </tr>    <tr>        <td align="center">VMware® Workstation 17 Pro</td>        <td align="left">17.6.0 build-24238078</td>      </tr>    <tr>        <td align="center">终端软件</td>        <td align="left">MobaXterm(Professional Edition v23.0 Build 5042 (license))</td>    </tr>    <tr>        <td align="center">Win32DiskImager</td>        <td align="left">Win32DiskImager v1.0</td>      </tr>    <tr>        <td align="center" rowspan="3">Linux开发板环境</td>        <td align="center">Linux开发板</td>        <td align="left">正点原子 i.MX6ULL Linux 阿尔法开发板</td>      </tr>    <tr>        <td align="center">uboot</td>        <td align="left">NXP官方提供的uboot，使用的uboot版本为U-Boot 2019.04</td>      </tr>    <tr>        <td align="center">linux内核</td>        <td align="left">linux-4.19.71(NXP官方提供)</td>      </tr></table>
              </div>
            </details>

<details class="folding-tag" blue><summary> 点击查看本文参考资料 </summary>
              <div class='content'>
              <table>    <tr>        <td align="center">分类</td>        <td align="center">网址</td>        <td align="center">说明</td>    </tr>    <tr>        <td align="center" rowspan="5">官方网站</td>        <td align="left"><a href="https://www.arm.com/" target="_blank">https://www.arm.com/</a></td>        <td align="left">ARM官方网站，在这里我们可以找到Cotex-Mx以及ARMVx的一些文档</td>    </tr>    <tr>        <td align="left"><a href="https://www.nxp.com.cn/" target="_blank">https://www.nxp.com.cn/ </a></td>        <td align="left">NXP官方网站</td>    </tr>    <tr>        <td align="left"><a href="https://www.nxpic.org.cn/" target="_blank">https://www.nxpic.org.cn/</a></td><td align="left">NXP 官方社区</td>    </tr>    <tr>        <td align="left"><a href="https://u-boot.readthedocs.io/en/latest/" target="_blank">https://u-boot.readthedocs.io/en/latest/</a></td><td align="left">u-boot官网</td>    </tr>    <tr>        <td align="left"><a href="https://www.kernel.org/" target="_blank">https://www.kernel.org/</a></td><td align="left">linux内核官网</td>    </tr>    <tr>        <td align="center" rowspan="5">其他网站</td>        <td align="left"><a href="https://elixir.bootlin.com/linux/v4.15/source/kernel" target="_blank">kernel - Linux source code (v4.15) - Bootlin</a></td>        <td align="left">linux内核源码在线查看</td>    </tr></table>
              </div>
            </details>

<details class="folding-tag" blue><summary> 点击查看相关文件下载 </summary>
              <div class='content'>
              <table>    <tr>        <td align="center">分类</td>        <td align="center">网址</td>        <td align="center">说明</td>    </tr>    <tr>        <td align="center" rowspan="3">NXP</td>        <td align="left"><a href="https://github.com/nxp-imx" target="_blank">https://github.com/nxp-imx</a></td>        <td align="left">NXP imx开发资源GitHub组织，里边会有u-boot和linux内核的仓库</td>    </tr>    <tr>        <td align="left"><a href="https://github.com/nxp-imx/linux-imx/releases/tag/v4.19.71" target="_blank">nxp-imx/linux-imx/releases/tag/v4.19.71</a></td>        <td align="left">NXP linux内核仓库tags中的v4.19.71</td>    </tr>    <tr>        <td align="left"><a href="https://github.com/nxp-imx/uboot-imx/releases/tag/rel_imx_4.19.35_1.1.0" target="_blank">nxp-imx/uboot-imx/releases/tag/rel_imx_4.19.35_1.1.0</a></td>        <td align="left">NXP u-boot仓库tags中的rel_imx_4.19.35_1.1.0</td>    </tr>    <tr>        <td align="center" rowspan="2">I.MX6ULL</td>        <td align="left"><a href="https://www.nxp.com.cn/docs/en/data-sheet/IMX6ULLIEC.pdf" target="_blank">i.MX 6ULL Applications Processors for Industrial Products</a></td>        <td align="left">I.MX6ULL 芯片手册（datasheet，可以在线查看）</td>    </tr>    <tr>        <td align="left"><a href="https://www.nxp.com.cn/webapp/Download?colCode=IMX6ULLRM&lang_cd=zh" target="_blank">i.MX 6ULL Applications ProcessorReference Manual</a></td>        <td align="left">I.MX6ULL 参考手册（下载后才能查看，需要登录NXP官网）</td>    </tr>    <tr>        <td align="center" rowspan="2">Source Code</td>        <td align="left"><a href="https://elixir.bootlin.com/linux/latest/source" target="_blank">https://elixir.bootlin.com/linux/latest/source</a></td>        <td align="left">linux kernel源码</td>    </tr>    <tr>        <td align="left"><a href="https://elixir.bootlin.com/u-boot/latest/source" target="_blank">https://elixir.bootlin.com/u-boot/latest/source</a></td>        <td align="left">uboot源码</td>    </tr></table>
              </div>
            </details>

<h1 id="一、为什么？"><a href="#一、为什么？" class="headerlink" title="一、为什么？"></a><font size=3>一、为什么？</font></h1><p>为什么要研究这个？因为linux内核的还没去学呢啊，主要是因为后面在搞驱动开发学习的时候需要这个。为什么？在驱动开发的时候，一般我是把驱动的源文件放在linux内核源码之外，通过调用内核的makefile来编译生成独立的内核模块，仓库在这里：<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/imx6ull-driver-demo">imx6ull-driver-demo: i.mx6ull驱动开发demo</a></p>
<p>因为我是进行了git版本管理的，在实际的工作中，也经常遇到不知道用的驱动是什么版本的问题，用的是这一个版本，随着功能的完善，版本肯定要迭代更新的，可是回头谁知道自己用的哪个驱动版本啊，也许有别的办法能追溯，但起码我写这个笔记的时候还没有接触到。</p>
<p>目前想到的办法就是把git版本号以及编译时间这些信息写进去，git版本号的获取可以在Makefile中这样获取：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">#GIT_SHA = $(shell git rev-list HEAD | awk &#x27;NR==1&#x27;)</span></span><br><span class="line">GIT_SHA = <span class="variable">$(<span class="built_in">shell</span> git rev-parse --short HEAD | awk &#x27;NR==1&#x27;)</span></span><br><span class="line">GIT_SEQ = <span class="variable">$(<span class="built_in">shell</span> git rev-list HEAD | wc -l)</span></span><br><span class="line">GIT_VER_INFO = <span class="variable">$(GIT_SHA)</span>-<span class="variable">$(GIT_SEQ)</span></span><br><span class="line">GIT_SVR_PATH = <span class="variable">$(<span class="built_in">shell</span> git remote -v | awk &#x27;NR==1&#x27; | sed &#x27;s/[()</span>]//g&#x27; | sed &#x27;s/\t/ /g&#x27; |cut -d <span class="string">&quot; &quot;</span> -f2)</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="keyword">ifneq</span> (<span class="variable">$(GIT_VER_INFO)</span>,)</span><br><span class="line">	CFLAGS += -DGIT_VERSION=\<span class="string">&quot;<span class="variable">$(GIT_VER_INFO)\&quot;</span></span></span><br><span class="line"><span class="string">else</span></span><br><span class="line"><span class="string">	CFLAGS += -DGIT_VERSION=\&quot;unknown\&quot;</span></span><br><span class="line"><span class="string">endif</span></span><br><span class="line"><span class="string"></span></span><br><span class="line"><span class="string">ifneq (<span class="variable">$(GIT_SVR_PATH)</span>,)</span></span><br><span class="line"><span class="string">	CFLAGS += -DGIT_PATH=\&quot;<span class="variable">$(GIT_SVR_PATH)\&quot;</span></span></span><br><span class="line"><span class="string">else</span></span><br><span class="line"><span class="string">	CFLAGS += -DGIT_PATH=\&quot;unknown\&quot;</span></span><br><span class="line"><span class="string">endif</span></span><br></pre></td></tr></table></figure>

<p>然后再GCC编译的时候加进去，就可以直接再c语言工程中调用了，但是吧有个问题，就是这样的-D参数是要加在编译工具后面的，例如：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">gcc -DDEBUG source.c -o program</span><br></pre></td></tr></table></figure>

<p>但是我们在内核源码之外写的驱动源文件，通过调用内核的makefile来编译的，经过实践发现，这里没办法直接把-D参数传给内核Makefile，至少写这个笔记的时候我还没发现怎么传进去让ko的源文件可以调用。所以我就去扒了uboot的源码，因为我们知道uboot是会生成两个文件的：</p>
<ul>
<li><a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/include/generated/timestamp_autogenerated.h">include&#x2F;generated&#x2F;timestamp_autogenerated.h · 苏木&#x2F;u-boot - 码云 - 开源中国</a></li>
</ul>
<figure class="highlight c"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">define</span> U_BOOT_DATE <span class="string">&quot;Nov 19 2024&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> U_BOOT_TIME <span class="string">&quot;21:45:10&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> U_BOOT_TZ <span class="string">&quot;+0800&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> U_BOOT_DMI_DATE <span class="string">&quot;11/19/2024&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> U_BOOT_BUILD_DATE 0x20241119</span></span><br></pre></td></tr></table></figure>

<ul>
<li><a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/include/generated/version_autogenerated.h">include&#x2F;generated&#x2F;version_autogenerated.h · 苏木&#x2F;u-boot - 码云 - 开源中国</a></li>
</ul>
<figure class="highlight c"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">define</span> PLAIN_VERSION <span class="string">&quot;2019.04-gf32bcf5b&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> U_BOOT_VERSION <span class="string">&quot;U-Boot &quot;</span> PLAIN_VERSION</span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> CC_VERSION_STRING <span class="string">&quot;arm-linux-gnueabihf-gcc (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36)) 8.3.0&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> LD_VERSION_STRING <span class="string">&quot;GNU ld (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36)) 2.32.0.20190321&quot;</span></span></span><br></pre></td></tr></table></figure>

<p>这里直接定义成了宏，生成的是头文件，这样我们直接在C工程中调用也可以，这样不就可以实现了吗，哈哈。所以就来看一下这两个文件怎么生成和创建的吧。</p>
<blockquote>
<p>Tips：在uboot的git管理中，这两个文件没有必要纳入版本库的管理，这里只是为了方便学习。另外将这个纳入版本库后，这个远程仓库中的version_autogenerated.h文件中git版本号永远都比最新一次提交落后，因为每次编译完，这个文件中都是最新一次提交的commit id，但是当我们传到远端的时候，在本地需要将所有的文件提交，这就会导致这个文件晚于最终的最新版本，当被重新编译的时候才会变成最新的。</p>
</blockquote>
<h1 id="二、timestamp"><a href="#二、timestamp" class="headerlink" title="二、timestamp"></a><font size=3>二、timestamp</font></h1><p>我们先来看这个关于时间的头文件都怎么生成的。</p>
<h2 id="1-编译信息"><a href="#1-编译信息" class="headerlink" title="1. 编译信息"></a><font size=3>1. 编译信息</font></h2><p>我们通过以下命令编译一次uboot，获取编译过程信息，看看里面关于这个文件的信息：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">make V=1 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- distclean</span><br><span class="line">make V=1 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- mx6ull_14x14_evk_defconfig</span><br><span class="line">make V=1 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j16 &gt; make_info.txt</span><br></pre></td></tr></table></figure>

<p>获取到这个make_info.txt文件后，我们打开搜索一下timestamp_autogenerated.h，就会发现所有相关的信息都在这里：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">set -e; : &#x27;  CHK     include/generated/timestamp_autogenerated.h&#x27;; mkdir -p include/generated/; 	(if test -n &quot;$&#123;SOURCE_DATE_EPOCH&#125;&quot;; then SOURCE_DATE=&quot;@$&#123;SOURCE_DATE_EPOCH&#125;&quot;; DATE=&quot;&quot;; for date in gdate date.gnu date; do $&#123;date&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; &gt;/dev/null 2&gt;&amp;1 &amp;&amp; DATE=&quot;$&#123;date&#125;&quot;; done; if test -n &quot;$&#123;DATE&#125;&quot;; then LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_TIME &quot;%T&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_TZ &quot;%z&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; else return 42; fi; else LC_ALL=C date +&#x27;#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_TIME &quot;%T&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_TZ &quot;%z&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; fi) &lt; Makefile &gt; include/generated/timestamp_autogenerated.h.tmp; if [ -r include/generated/timestamp_autogenerated.h ] &amp;&amp; cmp -s include/generated/timestamp_autogenerated.h include/generated/timestamp_autogenerated.h.tmp; then rm -f include/generated/timestamp_autogenerated.h.tmp; else : &#x27;  UPD     include/generated/timestamp_autogenerated.h&#x27;; mv -f include/generated/timestamp_autogenerated.h.tmp include/generated/timestamp_autogenerated.h; fi</span><br></pre></td></tr></table></figure>

<p>整理一下：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br></pre></td><td class="code"><pre><span class="line">set -e; : &#x27;  CHK     include/generated/timestamp_autogenerated.h&#x27;; </span><br><span class="line">mkdir -p include/generated/; 	</span><br><span class="line">(if test -n &quot;$&#123;SOURCE_DATE_EPOCH&#125;&quot;; then </span><br><span class="line">	SOURCE_DATE=&quot;@$&#123;SOURCE_DATE_EPOCH&#125;&quot;; </span><br><span class="line">	DATE=&quot;&quot;; </span><br><span class="line">	for date in gdate date.gnu date; do </span><br><span class="line"><span class="meta prompt_">		$</span><span class="language-bash">&#123;<span class="built_in">date</span>&#125; -u -d <span class="string">&quot;<span class="variable">$&#123;SOURCE_DATE&#125;</span>&quot;</span> &gt;/dev/null 2&gt;&amp;1 &amp;&amp; DATE=<span class="string">&quot;<span class="variable">$&#123;date&#125;</span>&quot;</span>;</span> </span><br><span class="line">	done; </span><br><span class="line">	if test -n &quot;$&#123;DATE&#125;&quot;; then </span><br><span class="line">		LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;;</span><br><span class="line">        LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_TIME &quot;%T&quot;&#x27;; </span><br><span class="line">        LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_TZ &quot;%z&quot;&#x27;; </span><br><span class="line">        LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;;</span><br><span class="line">        LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; </span><br><span class="line">	else </span><br><span class="line">		return 42; </span><br><span class="line">	fi; </span><br><span class="line">else </span><br><span class="line">	LC_ALL=C date +&#x27;#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; </span><br><span class="line">	LC_ALL=C date +&#x27;#define U_BOOT_TIME &quot;%T&quot;&#x27;; </span><br><span class="line">	LC_ALL=C date +&#x27;#define U_BOOT_TZ &quot;%z&quot;&#x27;; </span><br><span class="line">	LC_ALL=C date +&#x27;#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; </span><br><span class="line">	LC_ALL=C date +&#x27;#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; </span><br><span class="line">fi) </span><br><span class="line">&lt; Makefile &gt; include/generated/timestamp_autogenerated.h.tmp; </span><br><span class="line">if [ -r include/generated/timestamp_autogenerated.h ] &amp;&amp; cmp -s include/generated/timestamp_autogenerated.h include/generated/timestamp_autogenerated.h.tmp; then </span><br><span class="line">	rm -f include/generated/timestamp_autogenerated.h.tmp; </span><br><span class="line">else : &#x27;  UPD     include/generated/timestamp_autogenerated.h&#x27;; </span><br><span class="line">	mv -f include/generated/timestamp_autogenerated.h.tmp include/generated/timestamp_autogenerated.h; </span><br><span class="line">fi</span><br></pre></td></tr></table></figure>

<p>接下来我们就来看一看这个编译信息怎么出来的。</p>
<h2 id="2-timestamp-h"><a href="#2-timestamp-h" class="headerlink" title="2. timestamp_h"></a><font size=3>2. timestamp_h</font></h2><p>先找一下timestamp_autogenerated.h定义的位置，这个文件位置的定义是在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L448">Makefile · <em>timestamp_h</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">timestamp_h := <span class="keyword">include</span>/generated/timestamp_autogenerated.h</span><br></pre></td></tr></table></figure>

<p>看到这里定义了这个timestamp_h变量，我们接着搜一下这个timestamp_h关键词，会发现它也是一个目标，在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L1644">Makefile</a>中的规则如下：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="variable">$(timestamp_h)</span>: <span class="variable">$(srctree)</span>/Makefile FORCE</span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,timestamp.h)</span></span><br></pre></td></tr></table></figure>

<p>我们前面分析顶层Makefile的时候分析过，这个<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L201">Makefile · <em>srctree</em></a>最后是<code>.</code>，所以这里简单先展开一下就是：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="section">include/generated/timestamp_autogenerated.h: ./Makefile FORCE</span></span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,timestamp.h)</span></span><br></pre></td></tr></table></figure>

<p>接下来就是看这个filechk和timestamp.h是什么了。</p>
<h2 id="3-filechk"><a href="#3-filechk" class="headerlink" title="3. filechk"></a><font size=3>3. filechk</font></h2><h3 id="3-1-Makefile中的自定义函数"><a href="#3-1-Makefile中的自定义函数" class="headerlink" title="3.1 Makefile中的自定义函数"></a><font size=3>3.1 Makefile中的自定义函数</font></h3><p>我们先回顾一下Makefile中的自定义函数，在Makefile中是可以自己定义一个函数然后调用的。比如：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_timestamp.h</span><br><span class="line">	@echo <span class="string">&quot;this is a makefile function!&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;\$(0)=$(0)：表示函数名&quot;</span></span><br><span class="line">    @echo <span class="string">&quot;\$(1)=$(1)：表示传给函数的第一个参数&quot;</span></span><br><span class="line">    @echo <span class="string">&quot;\$(2)=$(2)：表示传给函数的第二个参数&quot;</span></span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<p>然后可以通过以下语句调用：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="variable">$(<span class="built_in">call</span> func_name,arg1,arg2,...)</span></span><br></pre></td></tr></table></figure>

<p>一般而言，call 本身并不具备编译功能，call 只是将自定义函数在当前位置展开，遇到Makefile内置函数会自动执行。其中arg1、arg2、…是传入函数的参数。我们可以尝试一下，新建一个Makefile文件，输入以下内容：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_timestamp</span><br><span class="line">	@echo <span class="string">&quot;this is a makefile function!&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;$(0)：表示函数名&quot;</span></span><br><span class="line">    @echo <span class="string">&quot;$(1)：表示传给函数的第一个参数&quot;</span></span><br><span class="line">    @echo <span class="string">&quot;$(2)：表示传给函数的第二个参数&quot;</span></span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line"><span class="section">test:</span></span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk_timestamp,arg1,arg2)</span></span><br></pre></td></tr></table></figure>

<p>我们直接执行make，就会得到如下打印信息：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">this is a makefile function!</span><br><span class="line">filechk_timestamp：表示函数名</span><br><span class="line">arg1：表示传给函数的第一个参数</span><br><span class="line">arg2：表示传给函数的第二个参数</span><br></pre></td></tr></table></figure>

<p>前面说到call 只是将自定义函数在当前位置展开，所以上面的函数其实等价于：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">#define filechk_timestamp</span></span><br><span class="line"><span class="comment">#	 @echo &quot;this is a makefile function!&quot;</span></span><br><span class="line"><span class="comment">#	 @echo &quot;$(0)：表示函数名&quot;</span></span><br><span class="line"><span class="comment">#    @echo &quot;$(1)：表示传给函数的第一个参数&quot;</span></span><br><span class="line"><span class="comment">#    @echo &quot;$(2)：表示传给函数的第二个参数&quot;</span></span><br><span class="line"><span class="comment">#endef</span></span><br><span class="line"></span><br><span class="line"><span class="section">test:</span></span><br><span class="line">	@echo <span class="string">&quot;this is a makefile function!&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;filechk_timestamp：表示函数名&quot;</span></span><br><span class="line">    @echo <span class="string">&quot;arg1：表示传给函数的第一个参数&quot;</span></span><br><span class="line">    @echo <span class="string">&quot;arg2：表示传给函数的第二个参数&quot;</span></span><br></pre></td></tr></table></figure>

<h3 id="3-2-filechk"><a href="#3-2-filechk" class="headerlink" title="3.2 filechk"></a><font size=3>3.2 filechk</font></h3><p>接下来我们来看一下这个filechk函数，它定义在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/scripts/Kbuild.include#L41">scripts&#x2F;Kbuild.include · <em>filechk</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment">###</span></span><br><span class="line"><span class="comment"># filechk is used to check if the content of a generated file is updated.</span></span><br><span class="line"><span class="comment"># Sample usage:</span></span><br><span class="line"><span class="comment"># define filechk_sample</span></span><br><span class="line"><span class="comment">#	echo $KERNELRELEASE</span></span><br><span class="line"><span class="comment"># endef</span></span><br><span class="line"><span class="comment"># version.h : Makefile</span></span><br><span class="line"><span class="comment">#	$(call filechk,sample)</span></span><br><span class="line"><span class="comment"># The rule defined shall write to stdout the content of the new file.</span></span><br><span class="line"><span class="comment"># The existing file will be compared with the new one.</span></span><br><span class="line"><span class="comment"># - If no file exist it is created</span></span><br><span class="line"><span class="comment"># - If the content differ the new file is used</span></span><br><span class="line"><span class="comment"># - If they are equal no change, and no timestamp update</span></span><br><span class="line"><span class="comment"># - stdin is piped in from the first prerequisite ($&lt;) so one has</span></span><br><span class="line"><span class="comment">#   to specify a valid file as first prerequisite (often the kbuild file)</span></span><br><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	<span class="variable">$(Q)</span>set -e;				\</span><br><span class="line">	<span class="variable">$(kecho)</span> &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		<span class="variable">$(kecho)</span> &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<p>可以看到这里的<code>$(1)</code>应该就是前面的timestamp.h，所以这里就是：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	<span class="variable">$(Q)</span>set -e;				\</span><br><span class="line">	<span class="variable">$(kecho)</span> &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	$(filechk_timestamp.h) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		<span class="variable">$(kecho)</span> &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<h3 id="3-3-变量的值"><a href="#3-3-变量的值" class="headerlink" title="3.3 变量的值"></a><font size=3>3.3 变量的值</font></h3><p>哪些变量都是啥啊？其实这这些<code>$@</code>、<code>$&lt;</code>都是在规则中确定的，我们省点事，加点打印信息好了，我们修改<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/scripts/Kbuild.include#L41">scripts&#x2F;Kbuild.include · <em>filechk</em></a> 中 filechk 函数如下：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line">define filechk</span><br><span class="line">	echo &quot;&quot; \</span><br><span class="line">	echo &quot;Q=$(Q)&quot; \</span><br><span class="line">	echo &quot;kecho=$(kecho)&quot; \</span><br><span class="line">	echo &quot;$$@=$@&quot; \</span><br><span class="line">	echo &quot;$$&lt;=$&lt;&quot; \</span><br><span class="line">	echo &quot;&quot; \</span><br><span class="line"><span class="meta prompt_">	$</span><span class="language-bash">(Q)<span class="built_in">set</span> -e;				\</span></span><br><span class="line"><span class="language-bash">	$(kecho) <span class="string">&#x27;  CHK     $@&#x27;</span>;		\</span></span><br><span class="line"><span class="language-bash">	<span class="built_in">mkdir</span> -p $(<span class="built_in">dir</span> <span class="variable">$@</span>);			\</span></span><br><span class="line"><span class="language-bash">	$(filechk_$(1)) &lt; $&lt; &gt; <span class="variable">$@</span>.tmp;		\</span></span><br><span class="line"><span class="language-bash">	<span class="keyword">if</span> [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; <span class="keyword">then</span>	\</span></span><br><span class="line"><span class="language-bash">		<span class="built_in">rm</span> -f <span class="variable">$@</span>.tmp;			\</span></span><br><span class="line"><span class="language-bash">	<span class="keyword">else</span>					\</span></span><br><span class="line"><span class="language-bash">		$(kecho) <span class="string">&#x27;  UPD     $@&#x27;</span>;	\</span></span><br><span class="line"><span class="language-bash">		<span class="built_in">mv</span> -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span></span><br><span class="line"><span class="language-bash">	<span class="keyword">fi</span></span></span><br><span class="line">endef</span><br></pre></td></tr></table></figure>

<p>可以找到有这么一条打印信息：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">echo &quot;&quot; echo &quot;Q=&quot; echo &quot;kecho=:&quot; echo &quot;$@=include/generated/timestamp_autogenerated.h&quot; echo &quot;$&lt;=Makefile&quot; echo &quot;&quot; set -e; : &#x27;  CHK     include/generated/timestamp_autogenerated.h&#x27;; mkdir -p include/generated/; 	(if test -n &quot;$&#123;SOURCE_DATE_EPOCH&#125;&quot;; then SOURCE_DATE=&quot;@$&#123;SOURCE_DATE_EPOCH&#125;&quot;; DATE=&quot;&quot;; for date in gdate date.gnu date; do $&#123;date&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; &gt;/dev/null 2&gt;&amp;1 &amp;&amp; DATE=&quot;$&#123;date&#125;&quot;; done; if test -n &quot;$&#123;DATE&#125;&quot;; then LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_TIME &quot;%T&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_TZ &quot;%z&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; LC_ALL=C $&#123;DATE&#125; -u -d &quot;$&#123;SOURCE_DATE&#125;&quot; +&#x27;#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; else return 42; fi; else LC_ALL=C date +&#x27;#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_TIME &quot;%T&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_TZ &quot;%z&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; LC_ALL=C date +&#x27;#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; fi) &lt; Makefile &gt; include/generated/timestamp_autogenerated.h.tmp; if [ -r include/generated/timestamp_autogenerated.h ] &amp;&amp; cmp -s include/generated/timestamp_autogenerated.h include/generated/timestamp_autogenerated.h.tmp; then rm -f include/generated/timestamp_autogenerated.h.tmp; else : &#x27;  UPD     include/generated/timestamp_autogenerated.h&#x27;; mv -f include/generated/timestamp_autogenerated.h.tmp include/generated/timestamp_autogenerated.h; fi</span><br></pre></td></tr></table></figure>

<p>可以看到这些就是我们添加的打印信息：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">echo &quot;&quot; echo &quot;Q=&quot; echo &quot;kecho=:&quot; echo &quot;$@=include/generated/timestamp_autogenerated.h&quot; echo &quot;$&lt;=Makefile&quot; echo &quot;&quot;</span><br></pre></td></tr></table></figure>

<h3 id="3-4-filehck展开"><a href="#3-4-filehck展开" class="headerlink" title="3.4 filehck展开"></a><font size=3>3.4 filehck展开</font></h3><p>所以这里我们对这个函数展开：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	set -e;				\</span><br><span class="line">	: &#x27;  CHK     <span class="keyword">include</span>/generated/timestamp_autogenerated.h&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> include/generated/timestamp_autogenerated.h)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; Makefile &gt; <span class="keyword">include</span>/generated/timestamp_autogenerated.h.tmp;		\</span><br><span class="line">	if [ -r <span class="keyword">include</span>/generated/timestamp_autogenerated.h ] &amp;&amp; cmp -s <span class="keyword">include</span>/generated/timestamp_autogenerated.h <span class="keyword">include</span>/generated/timestamp_autogenerated.h.tmp; then	\</span><br><span class="line">		rm -f <span class="keyword">include</span>/generated/timestamp_autogenerated.h.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		: &#x27;  UPD     <span class="keyword">include</span>/generated/timestamp_autogenerated.h&#x27;;	\</span><br><span class="line">		mv -f <span class="keyword">include</span>/generated/timestamp_autogenerated.h.tmp <span class="keyword">include</span>/generated/timestamp_autogenerated.h;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<ul>
<li><p>**<code>set -e</code>**：使脚本在遇到任何命令失败时立即终止。</p>
</li>
<li><p>这个<code>:</code>是啥意思？？？<code>:</code>在 shell 中是一个不执行任何操作的命令，在这里应该只是用于记录日志或者调试信息，因为从前面的打印信息可以看出这里会打印出来这条提示信息。</p>
</li>
<li><p><code>-r include/generated/timestamp_autogenerated.h </code>：检查这个文件是否可读。</p>
</li>
<li><p><code> cmp -s</code>：<code>cmp</code>这是一个用于比较两个文件内容的命令，但它不会输出任何内容，而是通过退出状态码来表示文件是否相同。<code>-s</code> 选项：静默模式，不输出任何内容，只通过退出状态码来表示结果。这个命令退出状态码为<code>0</code>表示文件内容完全相同，<code>1</code>表示文件内容不同，<code>&gt;1</code>表示发生错误。这里的逻辑就是判断新生成的文件timestamp_autogenerated.h.tmp与timestamp_autogenerated.h文件是否相同，若相同，这次就没有必要更新了，就把中间文件删掉，若不相同，就把timestamp_autogenerated.h.tmp重命名为timestamp_autogenerated.h。</p>
</li>
</ul>
<h3 id="3-5-filechk-1"><a href="#3-5-filechk-1" class="headerlink" title="3.5 filechk_$(1)"></a><font size=3>3.5 filechk_$(1)</font></h3><p>我们再来看一下这个<code>filechk_$(1)</code>，在调用filechk函数的时候是这样的：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="variable">$(<span class="built_in">call</span> filechk,timestamp.h)</span></span><br></pre></td></tr></table></figure>

<p>我们将<code>$(1)</code>替换后，就是：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$(filechk_timestamp.h) &lt; Makefile &gt; <span class="keyword">include</span>/generated/timestamp_autogenerated.h.tmp;</span><br></pre></td></tr></table></figure>

<p>这里我们看一下这个filechk_timestamp.h，它定义在顶层<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L1608">Makefile · <em>filechk_timestamp.h</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># The SOURCE_DATE_EPOCH mechanism requires a date that behaves like GNU date.</span></span><br><span class="line"><span class="comment"># The BSD date on the other hand behaves different and would produce errors</span></span><br><span class="line"><span class="comment"># with the misused &#x27;-d&#x27; switch.  Respect that and search a working date with</span></span><br><span class="line"><span class="comment"># well known pre- and suffixes for the GNU variant of date.</span></span><br><span class="line"><span class="keyword">define</span> filechk_timestamp.h</span><br><span class="line">	(if test -n <span class="string">&quot;$$&#123;SOURCE_DATE_EPOCH&#125;&quot;</span>; then \</span><br><span class="line">		SOURCE_DATE=<span class="string">&quot;@$$&#123;SOURCE_DATE_EPOCH&#125;&quot;</span>; \</span><br><span class="line">		DATE=<span class="string">&quot;&quot;</span>; \</span><br><span class="line">		for date in gdate date.gnu date; do \</span><br><span class="line">			$$&#123;date&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> &gt;/dev/null 2&gt;&amp;1 &amp;&amp; DATE=<span class="string">&quot;$$&#123;date&#125;&quot;</span>; \</span><br><span class="line">		done; \</span><br><span class="line">		if test -n <span class="string">&quot;$$&#123;DATE&#125;&quot;</span>; then \</span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; \</span></span><br><span class="line">		<span class="keyword">else</span> \</span><br><span class="line">			return 42; \</span><br><span class="line">		fi; \</span><br><span class="line">	<span class="keyword">else</span> \</span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; \</span></span><br><span class="line">	fi)</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<ul>
<li><code>if test -n</code>是判断字符串是否为空，我找了下顶层 <a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile">Makefile</a>，好像也没找到这个SOURCE_DATE_EPOCH的定义，SOURCE_DATE_EPOCH它是一个环境变量，通常用于构建过程中，以确保生成的二进制文件和相关文件具有确定的时间戳。加个打印信息就会发现，这里为空，所以走的是else的部分，非空的部分就没去仔细研究了。</li>
<li><code>LC_ALL=C</code>：这个是一个环境变量设置，用于覆盖所有本地化设置，使其使用 C 本地化。这意味着程序的行为将遵循 POSIX 标准，忽略用户的本地化设置。这对于确保跨平台一致性尤其有用，特别是在处理文本数据时。</li>
<li><code>date +&#39;#define ...&#39;</code>：这个就是以后面指定的格式获取时间字符串，放到终端执行以下就知道了：</li>
</ul>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">sumu@sumu-virtual-machine:~/7Linux/imx6ull-uboot$ LC_ALL=C date +&#x27;#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;</span><br><span class="line"><span class="meta prompt_">#</span><span class="language-bash">define U_BOOT_DATE <span class="string">&quot;Nov 22 2024&quot;</span></span></span><br></pre></td></tr></table></figure>

<p>因为走的是else分支，所以这里我们可以简化一下：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_timestamp.h</span><br><span class="line">	(LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;;)</span></span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>



<h3 id="3-6-timestamp-autogenerated-h"><a href="#3-6-timestamp-autogenerated-h" class="headerlink" title="3.6 timestamp_autogenerated.h"></a><font size=3>3.6 timestamp_autogenerated.h</font></h3><p>timestamp_autogenerated.h这个文件怎么生成的？上面已经分析了里面的内容怎么来的，那文件怎么创建的？其实在这里<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/scripts/Kbuild.include#L59">scripts&#x2F;Kbuild.include · <em>filechk</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$(filechk_$(1)) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;</span><br></pre></td></tr></table></figure>

<p>前面我们已经可以将这个展开了：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$(filechk_timestamp.h) &lt; Makefile &gt; <span class="keyword">include</span>/generated/timestamp_autogenerated.h.tmp;</span><br></pre></td></tr></table></figure>

<p>把这个filechk_timestamp.h也替换一下：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">(LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">    LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;;) &lt; Makefile &gt; include/generated/timestamp_autogenerated.h.tmp;</span></span><br></pre></td></tr></table></figure>

<p>这个用了两个重定向操作符<code>&lt;</code>和<code>&gt;</code>，<code>&lt;</code> 是输入重定向操作符，用于将文件内容作为命令的标准输入。这在处理文件内容时非常有用，可以避免手动输入数据或从命令行传递大量数据。<code>&gt;</code> 是重定向操作符，用于将命令的输出重定向到文件或其他目标。</p>
<p>所以这里的含义就是，将当前目录下的Makefile文件作为左边命令的输入（我并没有发现它有什么具体的作用，后面发现了再补充），将命令的结果重定向到include&#x2F;generated&#x2F;timestamp_autogenerated.h.tmp文件中去。当文件不存在的时候就会直接创建。</p>
<h2 id="4-规则展开"><a href="#4-规则展开" class="headerlink" title="4. 规则展开"></a><font size=3>4. 规则展开</font></h2><p>到这里为止，就可以把这个timestamp_h规则完全展开了，但是这里展开写的太长了，我们直接写一个单独的demo来演示效果：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_timestamp_autogenerated.h</span><br><span class="line">	(if test -n <span class="string">&quot;$$&#123;SOURCE_DATE_EPOCH&#125;&quot;</span>; then \</span><br><span class="line">		SOURCE_DATE=<span class="string">&quot;@$$&#123;SOURCE_DATE_EPOCH&#125;&quot;</span>; \</span><br><span class="line">		DATE=<span class="string">&quot;&quot;</span>; \</span><br><span class="line">		for date in gdate date.gnu date; do \</span><br><span class="line">			$$&#123;date&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> &gt;/dev/null 2&gt;&amp;1 &amp;&amp; DATE=<span class="string">&quot;$$&#123;date&#125;&quot;</span>; \</span><br><span class="line">		done; \</span><br><span class="line">		if test -n <span class="string">&quot;$$&#123;DATE&#125;&quot;</span>; then \</span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; \</span></span><br><span class="line">		<span class="keyword">else</span> \</span><br><span class="line">			return 42; \</span><br><span class="line">		fi; \</span><br><span class="line">	<span class="keyword">else</span> \</span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define U_BOOT_BUILD_DATE 0x%Y%m%d&#x27;; \</span></span><br><span class="line">	fi)</span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	set -e;				\</span><br><span class="line">	: &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		: &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line">srctree := .</span><br><span class="line">timestamp_h := timestamp_autogenerated.h</span><br><span class="line"></span><br><span class="line"><span class="variable">$(timestamp_h)</span>: <span class="variable">$(srctree)</span>/Makefile FORCE</span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,timestamp_autogenerated.h)</span></span><br><span class="line">	</span><br><span class="line">PHONY += FORCE</span><br><span class="line"><span class="section">FORCE:</span></span><br><span class="line"></span><br><span class="line"><span class="meta"><span class="keyword">.PHONY</span>: $(PHONY)</span></span><br><span class="line"></span><br></pre></td></tr></table></figure>

<p>其中FORCE是一个伪目标，他可以保证每次都执行timestamp_h规则，可以保证每次都更新time_stamp.h文件。</p>
<h1 id="三、version"><a href="#三、version" class="headerlink" title="三、version"></a><font size=3>三、version</font></h1><p>接下来我们看一下这个uboot的版本是怎么显示和获取的。我们前面知道<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/include/generated/version_autogenerated.h">version_autogenerated.h</a>这个文件的内容如下：</p>
<figure class="highlight c"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">define</span> PLAIN_VERSION <span class="string">&quot;2019.04-gf32bcf5b&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> U_BOOT_VERSION <span class="string">&quot;U-Boot &quot;</span> PLAIN_VERSION</span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> CC_VERSION_STRING <span class="string">&quot;arm-linux-gnueabihf-gcc (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36)) 8.3.0&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">define</span> LD_VERSION_STRING <span class="string">&quot;GNU ld (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36)) 2.32.0.20190321&quot;</span></span></span><br></pre></td></tr></table></figure>

<p>可以看到它包含了ubuntu的版本号、git版本信息、编译器和链接器的版本信息。下面我们来分析一下这些都是怎么生成的。</p>
<h2 id="1-编译信息-1"><a href="#1-编译信息-1" class="headerlink" title="1. 编译信息"></a><font size=3>1. 编译信息</font></h2><p>和上面一样，我们通过以下命令编译一次uboot，获取编译过程信息，看看里面关于这个文件的信息：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">make V=1 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- distclean</span><br><span class="line">make V=1 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- mx6ull_14x14_evk_defconfig</span><br><span class="line">make V=1 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- -j16 &gt; make_info.txt</span><br></pre></td></tr></table></figure>

<p>获取到这个make_info.txt文件后，我们打开搜索一下version_autogenerated.h，就会发现所有相关的信息都在这里：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">set -e; : &#x27;  CHK     include/generated/version_autogenerated.h&#x27;; mkdir -p include/generated/; 	(echo \#define PLAIN_VERSION \&quot;2019.04&quot;&quot;\&quot;; echo \#define U_BOOT_VERSION \&quot;U-Boot \&quot; PLAIN_VERSION; echo \#define CC_VERSION_STRING \&quot;$(LC_ALL=C arm-linux-gnueabihf-gcc --version | head -n 1)\&quot;; echo \#define LD_VERSION_STRING \&quot;$(LC_ALL=C arm-linux-gnueabihf-ld.bfd --version | head -n 1)\&quot;; ) &lt; include/config/uboot.release &gt; include/generated/version_autogenerated.h.tmp; if [ -r include/generated/version_autogenerated.h ] &amp;&amp; cmp -s include/generated/version_autogenerated.h include/generated/version_autogenerated.h.tmp; then rm -f include/generated/version_autogenerated.h.tmp; else : &#x27;  UPD     include/generated/version_autogenerated.h&#x27;; mv -f include/generated/version_autogenerated.h.tmp include/generated/version_autogenerated.h; fi</span><br></pre></td></tr></table></figure>

<p>整理一下：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line">set -e; : &#x27;  CHK     include/generated/version_autogenerated.h&#x27;; </span><br><span class="line">mkdir -p include/generated/; 	</span><br><span class="line">(echo \#define PLAIN_VERSION \&quot;2019.04&quot;&quot;\&quot;; </span><br><span class="line">echo \#define U_BOOT_VERSION \&quot;U-Boot \&quot; PLAIN_VERSION; </span><br><span class="line">echo \#define CC_VERSION_STRING \&quot;$(LC_ALL=C arm-linux-gnueabihf-gcc --version | head -n 1)\&quot;;</span><br><span class="line">echo \#define LD_VERSION_STRING \&quot;$(LC_ALL=C arm-linux-gnueabihf-ld.bfd --version | head -n 1)\&quot;; ) &lt; include/config/uboot.release &gt; include/generated/version_autogenerated.h.tmp; </span><br><span class="line">if [ -r include/generated/version_autogenerated.h ] &amp;&amp; cmp -s include/generated/version_autogenerated.h include/generated/version_autogenerated.h.tmp; then </span><br><span class="line">	rm -f include/generated/version_autogenerated.h.tmp; </span><br><span class="line">else </span><br><span class="line">	: &#x27;  UPD     include/generated/version_autogenerated.h&#x27;; </span><br><span class="line">	mv -f include/generated/version_autogenerated.h.tmp include/generated/version_autogenerated.h; </span><br><span class="line">fi</span><br></pre></td></tr></table></figure>

<p>接下来我们就来看一看这个编译信息怎么出来的。</p>
<h2 id="2-version-h"><a href="#2-version-h" class="headerlink" title="2. version_h"></a><font size=3>2. version_h</font></h2><p>和时间信息一样，我们先在顶层Makefile中找到version_h的定义： <a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L447">Makefile · <em>version_h</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">version_h := <span class="keyword">include</span>/generated/version_autogenerated.h</span><br></pre></td></tr></table></figure>

<p>这里定义了这个version_h变量，我们接着搜一下这个version_h关键词，会发现它也是一个目标，在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L1641">Makefile</a>中的规则如下：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="variable">$(version_h)</span>: <span class="keyword">include</span>/config/uboot.release FORCE</span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,version.h)</span></span><br></pre></td></tr></table></figure>

<p>发现这里和前面的 <a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L1644">Makefile · <em>timestamp.h</em></a> 一样，都是调用了filechk函数，这里简单展开一下：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="section">include/generated/version_autogenerated.h: include/config/uboot.release FORCE</span></span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,version_h)</span></span><br></pre></td></tr></table></figure>

<h2 id="3-filechk-1"><a href="#3-filechk-1" class="headerlink" title="3. filechk"></a><font size=3>3. filechk</font></h2><p>filechk函数前面已经找过了，它定义在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/scripts/Kbuild.include#L41">scripts&#x2F;Kbuild.include · <em>filechk</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	<span class="variable">$(Q)</span>set -e;				\</span><br><span class="line">	<span class="variable">$(kecho)</span> &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		<span class="variable">$(kecho)</span> &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<p>可以看到这里的<code>$(1)</code>应该就是前面的version_h，所以这里就是：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	<span class="variable">$(Q)</span>set -e;				\</span><br><span class="line">	<span class="variable">$(kecho)</span> &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	<span class="variable">$(filechk_version_h)</span> &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		<span class="variable">$(kecho)</span> &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<h3 id="3-1-变量的值"><a href="#3-1-变量的值" class="headerlink" title="3.1 变量的值"></a><font size=3>3.1 变量的值</font></h3><p>还是和前面一样，这些<code>$@</code>、<code>$&lt;</code>都是在规则中确定的，我们省点事，加点打印信息好了，我们修改<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/scripts/Kbuild.include#L41">scripts&#x2F;Kbuild.include · <em>filechk</em></a> 中 filechk 函数如下：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line">define filechk</span><br><span class="line">	echo &quot;&quot; \</span><br><span class="line">	echo &quot;Q=$(Q)&quot; \</span><br><span class="line">	echo &quot;kecho=$(kecho)&quot; \</span><br><span class="line">	echo &quot;$$@=$@&quot; \</span><br><span class="line">	echo &quot;$$&lt;=$&lt;&quot; \</span><br><span class="line">	echo &quot;&quot; \</span><br><span class="line"><span class="meta prompt_">	$</span><span class="language-bash">(Q)<span class="built_in">set</span> -e;				\</span></span><br><span class="line"><span class="language-bash">	$(kecho) <span class="string">&#x27;  CHK     $@&#x27;</span>;		\</span></span><br><span class="line"><span class="language-bash">	<span class="built_in">mkdir</span> -p $(<span class="built_in">dir</span> <span class="variable">$@</span>);			\</span></span><br><span class="line"><span class="language-bash">	$(filechk_$(1)) &lt; $&lt; &gt; <span class="variable">$@</span>.tmp;		\</span></span><br><span class="line"><span class="language-bash">	<span class="keyword">if</span> [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; <span class="keyword">then</span>	\</span></span><br><span class="line"><span class="language-bash">		<span class="built_in">rm</span> -f <span class="variable">$@</span>.tmp;			\</span></span><br><span class="line"><span class="language-bash">	<span class="keyword">else</span>					\</span></span><br><span class="line"><span class="language-bash">		$(kecho) <span class="string">&#x27;  UPD     $@&#x27;</span>;	\</span></span><br><span class="line"><span class="language-bash">		<span class="built_in">mv</span> -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span></span><br><span class="line"><span class="language-bash">	<span class="keyword">fi</span></span></span><br><span class="line">endef</span><br></pre></td></tr></table></figure>

<p>可以找到有这么一条打印信息：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">echo &quot;&quot; echo &quot;Q=&quot; echo &quot;kecho=:&quot; echo &quot;$@=include/generated/version_autogenerated.h&quot; echo &quot;$&lt;=include/config/uboot.release&quot; echo &quot;&quot; set -e; : &#x27;  CHK     include/generated/version_autogenerated.h&#x27;; mkdir -p include/generated/; 	(echo \#define PLAIN_VERSION \&quot;2019.04&quot;&quot;\&quot;; echo \#define U_BOOT_VERSION \&quot;U-Boot \&quot; PLAIN_VERSION; echo \#define CC_VERSION_STRING \&quot;$(LC_ALL=C arm-linux-gnueabihf-gcc --version | head -n 1)\&quot;; echo \#define LD_VERSION_STRING \&quot;$(LC_ALL=C arm-linux-gnueabihf-ld.bfd --version | head -n 1)\&quot;; ) &lt; include/config/uboot.release &gt; include/generated/version_autogenerated.h.tmp; if [ -r include/generated/version_autogenerated.h ] &amp;&amp; cmp -s include/generated/version_autogenerated.h include/generated/version_autogenerated.h.tmp; then rm -f include/generated/version_autogenerated.h.tmp; else : &#x27;  UPD     include/generated/version_autogenerated.h&#x27;; mv -f include/generated/version_autogenerated.h.tmp include/generated/version_autogenerated.h; fi</span><br></pre></td></tr></table></figure>

<p>可以看到这些就是我们添加的打印信息：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">echo &quot;&quot; echo &quot;Q=&quot; echo &quot;kecho=:&quot; echo &quot;$@=include/generated/version_autogenerated.h&quot; echo &quot;$&lt;=include/config/uboot.release&quot; echo &quot;&quot;</span><br></pre></td></tr></table></figure>

<h3 id="3-2-filehck展开"><a href="#3-2-filehck展开" class="headerlink" title="3.2 filehck展开"></a><font size=3>3.2 filehck展开</font></h3><p>所以这里我们对这个函数展开：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	set -e;				\</span><br><span class="line">	: &#x27;  CHK     <span class="keyword">include</span>/generated/version_autogenerated.h&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> include/generated/version_autogenerated.h)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; <span class="keyword">include</span>/config/uboot.release &gt; <span class="keyword">include</span>/generated/version_autogenerated.h.tmp;		\</span><br><span class="line">	if [ -r <span class="keyword">include</span>/generated/version_autogenerated.h ] &amp;&amp; cmp -s <span class="keyword">include</span>/generated/version_autogenerated.h <span class="keyword">include</span>/generated/version_autogenerated.h.tmp; then	\</span><br><span class="line">		rm -f <span class="keyword">include</span>/generated/version_autogenerated.h.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		: &#x27;  UPD     <span class="keyword">include</span>/generated/version_autogenerated.h&#x27;;	\</span><br><span class="line">		mv -f <span class="keyword">include</span>/generated/version_autogenerated.h.tmp <span class="keyword">include</span>/generated/version_autogenerated.h;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<p>这里和前面都是一样的。</p>
<h3 id="3-3-filechk-1"><a href="#3-3-filechk-1" class="headerlink" title="3.3 filechk_$(1)"></a><font size=3>3.3 filechk_$(1)</font></h3><h4 id="3-3-1-filechk-version-h"><a href="#3-3-1-filechk-version-h" class="headerlink" title="3.3.1 filechk_version.h"></a><font size=3>3.3.1 filechk_version.h</font></h4><p>我们再来看一下这个<code>filechk_$(1)</code>，在调用filechk函数的时候是这样的：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="variable">$(<span class="built_in">call</span> filechk,version.h)</span></span><br></pre></td></tr></table></figure>

<p>我们将<code>$(1)</code>替换后，就是：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">$(filechk_version.h) &lt; <span class="keyword">include</span>/config/uboot.release &gt; <span class="keyword">include</span>/generated/version_autogenerated.h.tmp;</span><br></pre></td></tr></table></figure>

<p>这里我们看一下这个filechk_version.h，它定义在顶层<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L1597">Makefile · <em>filechk_version.h</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_version.h</span><br><span class="line">	(echo \<span class="comment">#define PLAIN_VERSION \&quot;$(UBOOTRELEASE)\&quot;; \</span></span><br><span class="line">	echo \<span class="comment">#define U_BOOT_VERSION \&quot;U-Boot \&quot; PLAIN_VERSION; \</span></span><br><span class="line">	echo \<span class="comment">#define CC_VERSION_STRING \&quot;$$(LC_ALL=C $(CC) --version | head -n 1)\&quot;; \</span></span><br><span class="line">	echo \<span class="comment">#define LD_VERSION_STRING \&quot;$$(LC_ALL=C $(LD) --version | head -n 1)\&quot;; )</span></span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<ul>
<li>PLAIN_VERSION：这个的值由UBOOTRELEASE决定，我们后面再说。</li>
<li>U_BOOT_VERSION：这个是最终的uboot版本信息，它的内容与PLAIN_VERSION有关。</li>
<li>CC_VERSION_STRING是编译器的版本，我们可以在终端执行一下看看打印信息：</li>
</ul>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">sumu@sumu-virtual-machine:~/7Linux/imx6ull-uboot$ LC_ALL=C arm-linux-gnueabihf-gcc --version | head -n 1</span><br><span class="line">arm-linux-gnueabihf-gcc (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36)) 8.3.0</span><br></pre></td></tr></table></figure>

<ul>
<li>LD_VERSION_STRING是链接器的版本：</li>
</ul>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">sumu@sumu-virtual-machine:~/7Linux/imx6ull-uboot$ LC_ALL=C arm-linux-gnueabihf-ld --version | head -n 1</span><br><span class="line">GNU ld (GNU Toolchain for the A-profile Architecture 8.3-2019.03 (arm-rel-8.36)) 2.32.0.20190321</span><br></pre></td></tr></table></figure>

<p>接下来我们再来看看前面的uboot版本怎么得到的。</p>
<h4 id="3-3-2-UBOOTRELEASE"><a href="#3-3-2-UBOOTRELEASE" class="headerlink" title="3.3.2 UBOOTRELEASE"></a><font size=3>3.3.2 UBOOTRELEASE</font></h4><p>接下来我们看一下这个UBOOTRELEASE变量，它在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L390">Makefile · <em>UBOOTRELEASE</em></a>中有定义：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># Read UBOOTRELEASE from include/config/uboot.release (if it exists)</span></span><br><span class="line">UBOOTRELEASE = <span class="variable">$(<span class="built_in">shell</span> cat include/config/uboot.release 2&gt; /dev/null)</span></span><br></pre></td></tr></table></figure>

<p>可以看到它其实是获取了include&#x2F;config&#x2F;uboot.release文件的内容。接下来就是分析uboot.release的来源了。我们来看一下这个文件的内容：</p>
<img data-src="https://fanhua-picture.oss-cn-hangzhou.aliyuncs.com/01%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/LV05-02-U-Boot-07-uboot%E7%BC%96%E8%AF%91%E6%97%B6%E9%97%B4%E4%B8%8E%E7%89%88%E6%9C%AC/img/image-20241122215559817.png" alt="image-20241122215559817" />

<p>所以这里就对应了：</p>
<figure class="highlight c"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">define</span> PLAIN_VERSION <span class="string">&quot;2019.04-gf32bcf5b&quot;</span></span></span><br></pre></td></tr></table></figure>

<p>这个版本没对应上，可以发现是本地的上一个版本，这是因为，我们本地提交后，会产生一个新的git版本号，但是我们编译的时候是还没有提交的，所以这里就会晚一个版本啦，这个影响不大，这只是提交到版本库的记录会落后，我们拉到本地重新编译，这个文件就会更新成最新版本啦。</p>
<h3 id="3-4-uboot-release"><a href="#3-4-uboot-release" class="headerlink" title="3.4 uboot.release"></a><font size=3>3.4 uboot.release</font></h3><p>接下来就是看一看uboot.release中的内容来自于哪里？</p>
<h4 id="3-4-1-uboot-release规则"><a href="#3-4-1-uboot-release规则" class="headerlink" title="3.4.1 uboot.release规则"></a><font size=3>3.4.1 uboot.release规则</font></h4><p>我们这部分来分析一下。这个文件其实是编译后生成的，我们在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L1546">Makefile · <em>uboot.release</em></a>可以看到它的定义：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># Store (new) UBOOTRELEASE string in include/config/uboot.release</span></span><br><span class="line"><span class="section">include/config/uboot.release: include/config/auto.conf FORCE</span></span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,uboot.release)</span></span><br></pre></td></tr></table></figure>

<p>发现这里也是调用了filechk函数，并且传入的参数为uboot.release。</p>
<h4 id="3-4-3-filechk展开"><a href="#3-4-3-filechk展开" class="headerlink" title="3.4.3 filechk展开"></a><font size=3>3.4.3 filechk展开</font></h4><p>我们先看一下这个filechk函数，和前面是一样的，定义在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/scripts/Kbuild.include#L41">scripts&#x2F;Kbuild.include · <em>filechk</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	<span class="variable">$(Q)</span>set -e;				\</span><br><span class="line">	<span class="variable">$(kecho)</span> &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		<span class="variable">$(kecho)</span> &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<p>我们根据调用命令：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="variable">$(<span class="built_in">call</span> filechk,uboot.release)</span></span><br></pre></td></tr></table></figure>

<p>对其进行展开，我们前面知道：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br></pre></td><td class="code"><pre><span class="line">Q=</span><br><span class="line">kecho=:</span><br><span class="line"><span class="variable">$@</span>=<span class="keyword">include</span>/config/uboot.release</span><br><span class="line">@&lt;=<span class="keyword">include</span>/config/auto.conf</span><br><span class="line">$(1)=uboot.release</span><br></pre></td></tr></table></figure>

<p>所以这里是：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	set -e;				\</span><br><span class="line">	: &#x27;  CHK     <span class="keyword">include</span>/config/uboot.release&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> include/config/uboot.release)</span>;			\</span><br><span class="line">	$(filechk_uboot.release) &lt; <span class="keyword">include</span>/config/auto.conf &gt; <span class="keyword">include</span>/config/uboot.release.tmp;		\</span><br><span class="line">	if [ -r <span class="keyword">include</span>/config/uboot.release ] &amp;&amp; cmp -s <span class="keyword">include</span>/config/uboot.release <span class="keyword">include</span>/config/uboot.release.tmp; then	\</span><br><span class="line">		rm -f <span class="keyword">include</span>/config/uboot.release.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		: &#x27;  UPD     <span class="keyword">include</span>/config/uboot.release&#x27;;	\</span><br><span class="line">		mv -f <span class="keyword">include</span>/config/uboot.release.tmp <span class="keyword">include</span>/config/uboot.release;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<h4 id="3-4-2-filechk-1"><a href="#3-4-2-filechk-1" class="headerlink" title="3.4.2 filechk_$(1)"></a><font size=3>3.4.2 filechk_$(1)</font></h4><p>我们来看一下<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L1541">Makefile · <em>filechk_uboot.release</em></a>：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_uboot.release</span><br><span class="line">	echo <span class="string">&quot;<span class="variable">$(UBOOTVERSION)</span>$$(<span class="variable">$(CONFIG_SHELL)</span> <span class="variable">$(srctree)</span>/scripts/setlocalversion <span class="variable">$(srctree)</span>)&quot;</span></span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<ul>
<li>UBOOTVERSION，它定义在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L391">Makefile · <em>UBOOTVERSION</em></a>：</li>
</ul>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">UBOOTVERSION = <span class="variable">$(VERSION)</span><span class="variable">$(<span class="built_in">if</span> <span class="variable">$(PATCHLEVEL)</span>,.<span class="variable">$(PATCHLEVEL)</span>$(<span class="built_in">if</span> <span class="variable">$(SUBLEVEL)</span>,.<span class="variable">$(SUBLEVEL)</span>)</span>)<span class="variable">$(EXTRAVERSION)</span></span><br></pre></td></tr></table></figure>

<p>这里其实就是把<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L3">Makefile · <em>VERSION</em></a>这些版本号组合起来。</p>
<ul>
<li><p>srctree，之前分析过，这里是<code>.</code>。</p>
</li>
<li><p>CONFIG_SHELL，它定义在<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/Makefile#L251">Makefile · <em>CONFIG_SHELL</em></a></p>
</li>
</ul>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># SHELL used by kbuild</span></span><br><span class="line">CONFIG_SHELL := <span class="variable">$(<span class="built_in">shell</span> <span class="built_in">if</span> [ -x &quot;$$BASH&quot; ]; then echo $$BASH; \</span></span><br><span class="line"><span class="variable">	  else <span class="built_in">if</span> [ -x /bin/bash ]; then echo /bin/bash; \</span></span><br><span class="line"><span class="variable">	  else echo sh; fi ; fi)</span></span><br></pre></td></tr></table></figure>

<p>就不分析那几个变量了，我们直接从编译信息里找一下，我们去前面生成的make_info.txt中搜一下这个scripts&#x2F;setlocalversion关键词：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">set -e; : &#x27;  CHK     include/config/uboot.release&#x27;; mkdir -p include/config/; 	echo &quot;2019.04$(/bin/bash ./scripts/setlocalversion .)&quot; &lt; include/config/auto.conf &gt; include/config/uboot.release.tmp; if [ -r include/config/uboot.release ] &amp;&amp; cmp -s include/config/uboot.release include/config/uboot.release.tmp; then rm -f include/config/uboot.release.tmp; else : &#x27;  UPD     include/config/uboot.release&#x27;; mv -f include/config/uboot.release.tmp include/config/uboot.release; fi</span><br></pre></td></tr></table></figure>

<p>整理一下就是：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line">set -e; </span><br><span class="line">: &#x27;  CHK     include/config/uboot.release&#x27;; </span><br><span class="line">mkdir -p include/config/; 	</span><br><span class="line">echo &quot;2019.04$(/bin/bash ./scripts/setlocalversion .)&quot; &lt; include/config/auto.conf &gt; include/config/uboot.release.tmp; </span><br><span class="line">if [ -r include/config/uboot.release ] &amp;&amp; cmp -s include/config/uboot.release include/config/uboot.release.tmp; then </span><br><span class="line">	rm -f include/config/uboot.release.tmp; </span><br><span class="line">else </span><br><span class="line">	: &#x27;  UPD     include/config/uboot.release&#x27;; </span><br><span class="line">	mv -f include/config/uboot.release.tmp include/config/uboot.release; </span><br><span class="line">fi</span><br></pre></td></tr></table></figure>

<p>可以看到：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">$(filechk_uboot.release) &lt; <span class="keyword">include</span>/config/auto.conf &gt; <span class="keyword">include</span>/config/uboot.release.tmp;</span><br><span class="line"><span class="comment"># 对应的就是</span></span><br><span class="line">echo <span class="string">&quot;2019.04$(/bin/bash ./scripts/setlocalversion .)&quot;</span> &lt; <span class="keyword">include</span>/config/auto.conf &gt; <span class="keyword">include</span>/config/uboot.release.tmp; </span><br></pre></td></tr></table></figure>

<p>所以其实有：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_uboot.release</span><br><span class="line">	echo <span class="string">&quot;<span class="variable">$(UBOOTVERSION)</span>$$(<span class="variable">$(CONFIG_SHELL)</span> <span class="variable">$(srctree)</span>/scripts/setlocalversion <span class="variable">$(srctree)</span>)&quot;</span></span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 对应一下就是</span></span><br><span class="line"><span class="keyword">define</span> filechk_uboot.release</span><br><span class="line">	echo <span class="string">&quot;2019.04$(/bin/bash ./scripts/setlocalversion .)&quot;</span></span><br><span class="line">endf</span><br><span class="line"></span><br><span class="line"><span class="comment"># UBOOTVERSION=2019.04</span></span><br><span class="line"><span class="comment"># CONFIG_SHELL=/bin/bash</span></span><br><span class="line"><span class="comment"># srctree=.</span></span><br></pre></td></tr></table></figure>

<p>其实这里就是执行了scripts&#x2F;setlocalversion中的这个脚本并把脚本的结果和UBOOTVERSION拼接起来。然后通过<code>&gt;</code>将拼接后的字符串重定向到include&#x2F;config&#x2F;uboot.release.tmp文件中。</p>
<h3 id="3-5-setlocalversion"><a href="#3-5-setlocalversion" class="headerlink" title="3.5 setlocalversion"></a><font size=3>3.5 setlocalversion</font></h3><p>我们来看一下这个脚本 <a target="_blank" rel="noopener" href="https://gitee.com/sumumm/u-boot/blob/master/scripts/setlocalversion">scripts&#x2F;setlocalversion</a> 在做什么：</p>
<figure class="highlight shell"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta prompt_"># </span><span class="language-bash">This scripts adds <span class="built_in">local</span> version information from the version</span></span><br><span class="line"><span class="meta prompt_"># </span><span class="language-bash">control systems git, mercurial (hg) and subversion (svn).</span></span><br><span class="line"><span class="meta prompt_">#</span><span class="language-bash"></span></span><br><span class="line"><span class="language-bash"><span class="comment"># If something goes wrong, send a mail the kernel build mailinglist</span></span></span><br><span class="line"><span class="meta prompt_"># </span><span class="language-bash">(see MAINTAINERS) and CC Nico Schottelius</span></span><br><span class="line"><span class="meta prompt_"># </span><span class="language-bash">&lt;nico-linuxsetlocalversion -at- schottelius.org&gt;.</span></span><br><span class="line"><span class="meta prompt_">#</span><span class="language-bash"></span></span><br><span class="line"><span class="language-bash"><span class="comment">#</span></span></span><br></pre></td></tr></table></figure>

<p>根据前面的信息，可以看到这个其实是获取了git或者hg或者sv版本号，我们直接终端执行一下：</p>
<img data-src="https://fanhua-picture.oss-cn-hangzhou.aliyuncs.com/01%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91/02IMX6ULL%E5%B9%B3%E5%8F%B0/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/LV05-02-U-Boot-07-uboot%E7%BC%96%E8%AF%91%E6%97%B6%E9%97%B4%E4%B8%8E%E7%89%88%E6%9C%AC/img/image-20241122230044913.png" alt="image-20241122230044913" />

<p>所以这里得到的<code>&quot;&quot;-gde6d2f71-dirty</code>和前面的<code>2019.04</code>结合起来就是<code>2019.04&quot;&quot;-gde6d2f71-dirty</code></p>
<h2 id="4-生成git版本号"><a href="#4-生成git版本号" class="headerlink" title="4. 生成git版本号"></a><font size=3>4. 生成git版本号</font></h2><p>我们了解了uboot的git版本号生成过程，我们自己来写一个：</p>
<figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br></pre></td><td class="code"><pre><span class="line">UBOOTRELEASE=<span class="variable">$(<span class="built_in">shell</span> git rev-parse --verify --short HEAD)</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">define</span> filechk_version_autogenerated.h</span><br><span class="line">	(echo \<span class="comment">#define PLAIN_VERSION \&quot;$(UBOOTRELEASE)\&quot;; \</span></span><br><span class="line">	echo \<span class="comment">#define U_BOOT_VERSION \&quot;U-Boot \&quot; PLAIN_VERSION; \</span></span><br><span class="line">	echo \<span class="comment">#define CC_VERSION_STRING \&quot;$$(LC_ALL=C $(CC) --version | head -n 1)\&quot;; \</span></span><br><span class="line">	echo \<span class="comment">#define LD_VERSION_STRING \&quot;$$(LC_ALL=C $(LD) --version | head -n 1)\&quot;; )</span></span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	set -e;				\</span><br><span class="line">	: &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		: &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line">srctree := .</span><br><span class="line">version_h := version_autogenerated.h</span><br><span class="line"></span><br><span class="line">CC := arm-linux-gnueabihf-gcc</span><br><span class="line">LD := arm-linux-gnueabihf-ld</span><br><span class="line"></span><br><span class="line"><span class="keyword">export</span> LD CC</span><br><span class="line"></span><br><span class="line"><span class="variable">$(version_h)</span>: <span class="variable">$(srctree)</span>/Makefile FORCE</span><br><span class="line">	echo <span class="string">&quot;UBOOTRELEASE=&quot;</span><span class="variable">$(UBOOTRELEASE)</span></span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,version_autogenerated.h)</span></span><br><span class="line">	</span><br><span class="line">PHONY += FORCE</span><br><span class="line"><span class="section">FORCE:</span></span><br><span class="line"></span><br><span class="line"><span class="meta"><span class="keyword">.PHONY</span>: $(PHONY)</span></span><br><span class="line"></span><br></pre></td></tr></table></figure>

<h1 id="四、应用实例"><a href="#四、应用实例" class="headerlink" title="四、应用实例"></a><font size=3>四、应用实例</font></h1><p>这里先写一个在内核模块中打印编译时间和版本信息的实例。整体可以看这里：<a target="_blank" rel="noopener" href="https://gitee.com/sumumm/imx6ull-driver-demo/tree/master/03_module_basic/03_printk_prj_info">03_module_basic&#x2F;03_printk_prj_info · 苏木&#x2F;imx6ull-driver-demo - 码云 - 开源中国</a></p>
<h2 id="1-Kbuild-include"><a href="#1-Kbuild-include" class="headerlink" title="1. Kbuild.include"></a><font size=3>1. Kbuild.include</font></h2><figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">define</span> filechk_timestamp_autogenerated.h</span><br><span class="line">	(if test -n <span class="string">&quot;$$&#123;SOURCE_DATE_EPOCH&#125;&quot;</span>; then \</span><br><span class="line">		SOURCE_DATE=<span class="string">&quot;@$$&#123;SOURCE_DATE_EPOCH&#125;&quot;</span>; \</span><br><span class="line">		DATE=<span class="string">&quot;&quot;</span>; \</span><br><span class="line">		for date in gdate date.gnu date; do \</span><br><span class="line">			$$&#123;date&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> &gt;/dev/null 2&gt;&amp;1 &amp;&amp; DATE=<span class="string">&quot;$$&#123;date&#125;&quot;</span>; \</span><br><span class="line">		done; \</span><br><span class="line">		if test -n <span class="string">&quot;$$&#123;DATE&#125;&quot;</span>; then \</span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define  KERNEL_KO_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define KERNEL_KO_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define KERNEL_KO_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define KERNEL_KO_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">			LC_ALL=C $$&#123;DATE&#125; -u -d <span class="string">&quot;$$&#123;SOURCE_DATE&#125;&quot;</span> +&#x27;<span class="comment">#define KERNEL_KO_BUILD_DATE 0x%Y%m%d&#x27;; \</span></span><br><span class="line">		<span class="keyword">else</span> \</span><br><span class="line">			return 42; \</span><br><span class="line">		fi; \</span><br><span class="line">	<span class="keyword">else</span> \</span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define KERNEL_KO_DATE &quot;%b %d %C%y&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define KERNEL_KO_TIME &quot;%T&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define KERNEL_KO_TZ &quot;%z&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define KERNEL_KO_DMI_DATE &quot;%m/%d/%Y&quot;&#x27;; \</span></span><br><span class="line">		LC_ALL=C date +&#x27;<span class="comment">#define KERNEL_KO_BUILD_DATE 0x%Y%m%d&#x27;; \</span></span><br><span class="line">	fi)</span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">define</span> filechk_version_autogenerated.h</span><br><span class="line">	(echo \<span class="comment">#define PLAIN_VERSION \&quot;$(KERNEL_KO_RELEASE)\&quot;; \</span></span><br><span class="line">	echo \<span class="comment">#define KERNEL_KO_VERSION \&quot;\&quot; PLAIN_VERSION; \</span></span><br><span class="line">	echo \<span class="comment">#define CC_VERSION_STRING \&quot;$$(LC_ALL=C $(CC) --version | head -n 1)\&quot;; \</span></span><br><span class="line">	echo \<span class="comment">#define LD_VERSION_STRING \&quot;$$(LC_ALL=C $(LD) --version | head -n 1)\&quot;; )</span></span><br><span class="line"><span class="keyword">endef</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">define</span> filechk</span><br><span class="line">	<span class="variable">$(Q)</span>set -e;				\</span><br><span class="line">	: &#x27;  CHK     <span class="variable">$@</span>&#x27;;		\</span><br><span class="line">	mkdir -p <span class="variable">$(<span class="built_in">dir</span> <span class="variable">$@</span>)</span>;			\</span><br><span class="line">	$(filechk_$(1)) &lt; <span class="variable">$&lt;</span> &gt; <span class="variable">$@</span>.tmp;		\</span><br><span class="line">	if [ -r <span class="variable">$@</span> ] &amp;&amp; cmp -s <span class="variable">$@</span> <span class="variable">$@</span>.tmp; then	\</span><br><span class="line">		rm -f <span class="variable">$@</span>.tmp;			\</span><br><span class="line">	<span class="keyword">else</span>					\</span><br><span class="line">		: &#x27;  UPD     <span class="variable">$@</span>&#x27;;	\</span><br><span class="line">		mv -f <span class="variable">$@</span>.tmp <span class="variable">$@</span>;		\</span><br><span class="line">	fi</span><br><span class="line"><span class="keyword">endef</span></span><br></pre></td></tr></table></figure>

<h2 id="2-Makefile"><a href="#2-Makefile" class="headerlink" title="2. Makefile"></a><font size=3>2. Makefile</font></h2><figure class="highlight makefile"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br><span class="line">43</span><br><span class="line">44</span><br><span class="line">45</span><br><span class="line">46</span><br><span class="line">47</span><br><span class="line">48</span><br><span class="line">49</span><br><span class="line">50</span><br><span class="line">51</span><br><span class="line">52</span><br><span class="line">53</span><br><span class="line">54</span><br><span class="line">55</span><br><span class="line">56</span><br><span class="line">57</span><br><span class="line">58</span><br><span class="line">59</span><br><span class="line">60</span><br><span class="line">61</span><br><span class="line">62</span><br><span class="line">63</span><br><span class="line">64</span><br><span class="line">65</span><br><span class="line">66</span><br><span class="line">67</span><br><span class="line">68</span><br><span class="line">69</span><br><span class="line">70</span><br><span class="line">71</span><br><span class="line">72</span><br><span class="line">73</span><br><span class="line">74</span><br><span class="line">75</span><br><span class="line">76</span><br><span class="line">77</span><br><span class="line">78</span><br><span class="line">79</span><br><span class="line">80</span><br><span class="line">81</span><br><span class="line">82</span><br><span class="line">83</span><br><span class="line">84</span><br><span class="line">85</span><br><span class="line">86</span><br><span class="line">87</span><br><span class="line">88</span><br><span class="line">89</span><br><span class="line">90</span><br><span class="line">91</span><br><span class="line">92</span><br><span class="line">93</span><br><span class="line">94</span><br><span class="line">95</span><br><span class="line">96</span><br><span class="line">97</span><br><span class="line">98</span><br><span class="line">99</span><br><span class="line">100</span><br><span class="line">101</span><br><span class="line">102</span><br><span class="line">103</span><br><span class="line">104</span><br><span class="line">105</span><br><span class="line">106</span><br><span class="line">107</span><br><span class="line">108</span><br><span class="line">109</span><br><span class="line">110</span><br><span class="line">111</span><br><span class="line">112</span><br><span class="line">113</span><br><span class="line">114</span><br><span class="line">115</span><br><span class="line">116</span><br></pre></td><td class="code"><pre><span class="line"><span class="comment"># 模块名和模块测试APP名称</span></span><br><span class="line">MODULE_NAME       := printk_prj_info</span><br><span class="line"></span><br><span class="line">ARCH              ?= arm</span><br><span class="line">MAKE_PARAM        :=</span><br><span class="line">CURRENT_PATH      := <span class="variable">$(<span class="built_in">shell</span> pwd)</span></span><br><span class="line">KERNEL_KO_RELEASE  = <span class="variable">$(<span class="built_in">shell</span> git rev-parse --verify --short HEAD)</span></span><br><span class="line"><span class="keyword">ifeq</span> (<span class="string">&quot;$(origin V)&quot;</span>, <span class="string">&quot;command line&quot;</span>)</span><br><span class="line">  KBUILD_VERBOSE = <span class="variable">$(V)</span></span><br><span class="line"><span class="keyword">endif</span></span><br><span class="line"><span class="keyword">ifndef</span> KBUILD_VERBOSE</span><br><span class="line">  KBUILD_VERBOSE = 0</span><br><span class="line"><span class="keyword">endif</span></span><br><span class="line"></span><br><span class="line"><span class="keyword">ifeq</span> (<span class="variable">$(KBUILD_VERBOSE)</span>,1)</span><br><span class="line">  quiet =</span><br><span class="line">  Q =</span><br><span class="line"><span class="keyword">else</span></span><br><span class="line">  quiet=quiet_</span><br><span class="line">  Q = @</span><br><span class="line"><span class="keyword">endif</span></span><br><span class="line"></span><br><span class="line"><span class="comment">#=====================================================</span></span><br><span class="line">INCDIRS 		  := ./ 			   </span><br><span class="line">SRCDIRS			  := ./</span><br><span class="line"></span><br><span class="line">INCLUDE			  := <span class="variable">$(<span class="built_in">patsubst</span> %, -I %, <span class="variable">$(INCDIRS)</span>)</span></span><br><span class="line"><span class="comment">#=====================================================</span></span><br><span class="line"><span class="comment"># NFS 共享目录</span></span><br><span class="line">TFTP_SERVER       ?= ~/3tftp</span><br><span class="line">NFS_SERVER        ?= ~/4nfs</span><br><span class="line"></span><br><span class="line">TFTP_DIR          ?= <span class="variable">$(TFTP_SERVER)</span></span><br><span class="line">ROOTFS_ROOT_DIR   ?= <span class="variable">$(NFS_SERVER)</span>/imx6ull_rootfs</span><br><span class="line"><span class="comment">#ROOTFS_MODULE_DIR ?= $(ROOTFS_ROOT_DIR)/lib/modules/4.19.71-00007-g51f3cd8ec-dirty</span></span><br><span class="line">ROOTFS_MODULE_DIR ?= <span class="variable">$(ROOTFS_ROOT_DIR)</span>/drivers_demo</span><br><span class="line"><span class="comment">#=====================================================</span></span><br><span class="line"><span class="keyword">ifeq</span> (<span class="variable">$(KERNELRELEASE)</span>,)</span><br><span class="line"></span><br><span class="line"><span class="comment"># 选择可执行文件运行的平台</span></span><br><span class="line"><span class="keyword">ifeq</span> (<span class="variable">$(ARCH)</span>, arm)</span><br><span class="line">KERNELDIR            ?= ~/7Linux/imx6ull-kernel </span><br><span class="line">MAKE_PARAM           += ARCH=arm</span><br><span class="line">MAKE_PARAM           += CROSS_COMPILE=arm-linux-gnueabihf-</span><br><span class="line">CROSS_COMPILE_PREFIX ?= arm-linux-gnueabihf-</span><br><span class="line"><span class="keyword">else</span></span><br><span class="line">KERNELDIR            ?= /lib/modules/<span class="variable">$(<span class="built_in">shell</span> uname -r)</span>/build</span><br><span class="line">CROSS_COMPILE_PREFIX ?=</span><br><span class="line"><span class="keyword">endif</span></span><br><span class="line"></span><br><span class="line">CC                   := <span class="variable">$(CROSS_COMPILE_PREFIX)</span>gcc</span><br><span class="line">LD                   := <span class="variable">$(CROSS_COMPILE_PREFIX)</span>ld</span><br><span class="line"></span><br><span class="line"><span class="keyword">include</span> Kbuild.<span class="keyword">include</span></span><br><span class="line"></span><br><span class="line">srctree              := .</span><br><span class="line">timestamp_h          := timestamp_autogenerated.h</span><br><span class="line">version_h            := version_autogenerated.h</span><br><span class="line"></span><br><span class="line"><span class="keyword">export</span> CC LD srctree</span><br><span class="line"></span><br><span class="line"><span class="comment"># 编译模块和测试程序</span></span><br><span class="line"><span class="section">all: <span class="variable">$(timestamp_h)</span> <span class="variable">$(version_h)</span> modules</span></span><br><span class="line"></span><br><span class="line"><span class="section">modules:</span></span><br><span class="line">	<span class="variable">$(MAKE)</span> <span class="variable">$(MAKE_PARAM)</span> -C <span class="variable">$(KERNELDIR)</span> M=<span class="variable">$(CURRENT_PATH)</span> modules <span class="variable">$(INCLUDE)</span></span><br><span class="line"></span><br><span class="line"><span class="section">modules_install:</span></span><br><span class="line">	<span class="variable">$(MAKE)</span> <span class="variable">$(MAKE_PARAM)</span> -C <span class="variable">$(KERNELDIR)</span> M=<span class="variable">$(CURRENT_PATH)</span> modules INSTALL_MOD_PATH=<span class="variable">$(ROOTFS_MODULE_DIR)</span> modules_install</span><br><span class="line"></span><br><span class="line"><span class="variable">$(timestamp_h)</span>: <span class="variable">$(srctree)</span>/Makefile FORCE</span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,timestamp_autogenerated.h)</span></span><br><span class="line">	</span><br><span class="line"><span class="variable">$(version_h)</span>: <span class="variable">$(srctree)</span>/Makefile FORCE</span><br><span class="line">	<span class="variable">$(<span class="built_in">call</span> filechk,version_autogenerated.h)</span></span><br><span class="line"></span><br><span class="line"><span class="comment"># 拷贝相关文件到nfs共享目录</span></span><br><span class="line"><span class="section">install:</span></span><br><span class="line">	@sudo cp -v <span class="variable">$(MODULE_NAME)</span>.ko <span class="variable">$(ROOTFS_MODULE_DIR)</span></span><br><span class="line"></span><br><span class="line"><span class="section">uninstall:</span></span><br><span class="line">	@sudo rm -vf <span class="variable">$(ROOTFS_MODULE_DIR)</span>/<span class="variable">$(MODULE_NAME)</span>.ko </span><br><span class="line"></span><br><span class="line">PHONY += FORCE</span><br><span class="line"><span class="section">FORCE:</span></span><br><span class="line"></span><br><span class="line">PHONY += clean</span><br><span class="line"><span class="section">clean:</span></span><br><span class="line">	rm -rf *.o *.ko *.o.d</span><br><span class="line">	rm -rf .*.cmd  *.mod.* *.mod modules.order Module.symvers .tmp_versions .cache.mk </span><br><span class="line">	rm -rf <span class="variable">$(timestamp_h)</span></span><br><span class="line">	rm -rf <span class="variable">$(version_h)</span></span><br><span class="line"></span><br><span class="line"><span class="meta"><span class="keyword">.PHONY</span>: $(PHONY)</span></span><br><span class="line"></span><br><span class="line"><span class="section">help:</span></span><br><span class="line">	@echo <span class="string">&quot;\033[1;32m================================ Help ================================\033[0m&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;Ubuntu may need to add sudo:&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;insmod &lt;module_name&gt;.ko   # Load module&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;rmmod &lt;module_name&gt;       # Uninstall the module&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;dmesg -C                  # Clear the kernel print information&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;lsmod                     # Check the kernel modules that have been inserted&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;dmesg                     # View information printed by the kernel&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;file &lt;module_name&gt;.ko     # View \&quot;.Ko\&quot; file information&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;make ARCH=x86_64          # x86_64 platform&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;make                      # arm platform&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;\033[1;32m======================================================================\033[0m&quot;</span></span><br><span class="line"></span><br><span class="line"><span class="section">print:</span></span><br><span class="line">	@echo <span class="string">&quot;KERNELDIR = <span class="variable">$(KERNELDIR)</span>&quot;</span></span><br><span class="line">	@echo <span class="string">&quot;INCLUDE   = <span class="variable">$(INCLUDE)</span>&quot;</span></span><br><span class="line"><span class="keyword">else</span></span><br><span class="line">CONFIG_MODULE_SIG = n</span><br><span class="line">obj-m            += <span class="variable">$(MODULE_NAME)</span>.o</span><br><span class="line"><span class="keyword">endif</span></span><br></pre></td></tr></table></figure>

<h2 id="3-printk-prj-info-c"><a href="#3-printk-prj-info-c" class="headerlink" title="3. printk_prj_info.c"></a><font size=3>3. printk_prj_info.c</font></h2><figure class="highlight c"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br><span class="line">34</span><br><span class="line">35</span><br><span class="line">36</span><br><span class="line">37</span><br><span class="line">38</span><br><span class="line">39</span><br><span class="line">40</span><br><span class="line">41</span><br><span class="line">42</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;linux/kernel.h&gt;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;linux/init.h&gt;</span>     <span class="comment">/* module_init module_exit */</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&lt;linux/module.h&gt;</span>   <span class="comment">/* MODULE_LICENSE */</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&quot;./timestamp_autogenerated.h&quot;</span></span></span><br><span class="line"><span class="meta">#<span class="keyword">include</span> <span class="string">&quot;./version_autogenerated.h&quot;</span></span></span><br><span class="line"></span><br><span class="line"><span class="comment">// 模块入口函数</span></span><br><span class="line"><span class="type">static</span> <span class="type">int</span> __init <span class="title function_">printk_demo_init</span><span class="params">(<span class="type">void</span>)</span></span><br><span class="line">&#123;</span><br><span class="line">    printk(<span class="string">&quot;*** [%s:%d]Build Time: %s %s, git version:%s ***\n&quot;</span>, __FUNCTION__, __LINE__, KERNEL_KO_DATE, KERNEL_KO_TIME, KERNEL_KO_VERSION);</span><br><span class="line">    printk(<span class="string">&quot;printk_demo module init!\n&quot;</span>);</span><br><span class="line"></span><br><span class="line">    printk(KERN_EMERG<span class="string">&quot;KERN_EMERG:%s\r\n&quot;</span>, KERN_EMERG);</span><br><span class="line">    printk(KERN_ALERT<span class="string">&quot;KERN_ALERT:%s\r\n&quot;</span>, KERN_ALERT);</span><br><span class="line">    printk(KERN_CRIT<span class="string">&quot;KERN_CRIT:%s\r\n&quot;</span>, KERN_CRIT);</span><br><span class="line">    printk(KERN_ERR<span class="string">&quot;KERN_ERR:%s\r\n&quot;</span>, KERN_ERR);</span><br><span class="line">    printk(KERN_WARNING<span class="string">&quot;KERN_WARNING:%s\r\n&quot;</span>, KERN_WARNING);</span><br><span class="line">    printk(KERN_NOTICE<span class="string">&quot;KERN_NOTICE:%s\r\n&quot;</span>, KERN_NOTICE);</span><br><span class="line">    printk(KERN_INFO<span class="string">&quot;KERN_INFO:%s\r\n&quot;</span>, KERN_INFO);</span><br><span class="line">    printk(KERN_DEBUG<span class="string">&quot;KERN_DEBUG:%s\r\n&quot;</span>, KERN_DEBUG);</span><br><span class="line">	<span class="keyword">return</span> <span class="number">0</span>;</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">// 模块出口函数</span></span><br><span class="line"><span class="type">static</span> <span class="type">void</span> __exit <span class="title function_">printk_demo_exit</span><span class="params">(<span class="type">void</span>)</span></span><br><span class="line">&#123;</span><br><span class="line">	printk(<span class="string">&quot;printk_demo exit!\n&quot;</span>);</span><br><span class="line">&#125;</span><br><span class="line"></span><br><span class="line"><span class="comment">// 将__init定义的函数指定为驱动的入口函数</span></span><br><span class="line">module_init(printk_demo_init);</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="comment">// 将__exit定义的函数指定为驱动的出口函数</span></span><br><span class="line">module_exit(printk_demo_exit);</span><br><span class="line"></span><br><span class="line"><span class="comment">/* 模块信息(通过 modinfo printk_demo 查看) */</span></span><br><span class="line">MODULE_LICENSE(<span class="string">&quot;GPL&quot;</span>);               <span class="comment">/* 源码的许可证协议 */</span></span><br><span class="line">MODULE_AUTHOR(<span class="string">&quot;sumu&quot;</span>);               <span class="comment">/* 字符串常量内容为模块作者说明 */</span></span><br><span class="line">MODULE_DESCRIPTION(<span class="string">&quot;Description&quot;</span>);   <span class="comment">/* 字符串常量内容为模块功能说明 */</span></span><br><span class="line">MODULE_ALIAS(<span class="string">&quot;module&#x27;s other name&quot;</span>); <span class="comment">/* 字符串常量内容为模块别名 */</span></span><br><span class="line"></span><br></pre></td></tr></table></figure>


    </div>

    
    
    

    <footer class="post-footer">




    <div>
        
            <div style="text-align:center;color: #ccc;font-size:14px;">
            ----------本文结束
            <i class="fas fa-fan fa-spin" style="color: #FF1493; font-size: 1rem"></i>
            感谢您的阅读----------
            </div>
        
    </div>





  
  <div class="my_post_copyright"> 
    <p><span>文章标题:</span><a href="/post/f68c951e.html">LV05-02-U-Boot-07-uboot编译时间与版本</a></p>
    <p><span>文章作者:</span><a href="/" title="欢迎访问 《苏木》 的学习笔记">苏木</a></p>
    <p><span>发布时间:</span>2024年11月24日 - 18:12</p>
    <p><span>最后更新:</span>2025年06月14日 - 00:25</p>
    <p><span>原始链接:</span><a href="/post/f68c951e.html" title="LV05-02-U-Boot-07-uboot编译时间与版本">https://sumumm.github.io/post/f68c951e.html</a></p>
    <p><span>许可协议:</span><i class="fab fa-creative-commons"></i> <a rel="license" href= "https://creativecommons.org/licenses/by-nc-nd/4.0/" target="_blank" title="Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)">署名-非商业性使用-禁止演绎 4.0 国际</a> 转载请保留原文链接及作者。</p>  
  </div>
  


          <div class="post-tags">
              <a href="/tags/LV05-%E7%B3%BB%E7%BB%9F%E9%95%9C%E5%83%8F/" rel="tag"><i class="fa fa-tag"></i> LV05-系统镜像</a>
          </div>

        

          <div class="post-nav">
            <div class="post-nav-item">
                <a href="/post/549b1511.html" rel="prev" title="LV06-02-内核模块-04-内核模块的工作机制">
                  <i class="fa fa-angle-left"></i> LV06-02-内核模块-04-内核模块的工作机制
                </a>
            </div>
            <div class="post-nav-item">
                <a href="/post/6dad760f.html" rel="next" title="LV05-06-系统烧写-02-img镜像文件">
                  LV05-06-系统烧写-02-img镜像文件 <i class="fa fa-angle-right"></i>
                </a>
            </div>
          </div>
    </footer>
  </article>
</div>






</div>
  </main>

  <footer class="footer">
    <div class="footer-inner">

  <div class="copyright">
    &copy; 2017 – 
    <span itemprop="copyrightYear">2025</span>
    <span class="with-love">
      <i class="fa fa-heart"></i>
    </span>
    <span class="author" itemprop="copyrightHolder">苏木</span>
  </div>
<div class="wordcount">
  <span class="post-meta-item">
    <span class="post-meta-item-icon">
      <i class="fa fa-chart-line"></i>
    </span>
      <span>站点总字数：</span>
    <span title="站点总字数">3.7m</span>
  </span>
  <span class="post-meta-item">
    <span class="post-meta-item-icon">
      <i class="fa fa-coffee"></i>
    </span>
      <span>站点阅读时长 &asymp;</span>
    <span title="站点阅读时长">225:26</span>
  </span>
</div>




    <span id="sitetime"></span>
    <script defer language=javascript>
        function siteTime()
        {
            window.setTimeout("siteTime()", 1000);
            var seconds = 1000;
            var minutes = seconds * 60;
            var hours = minutes * 60;
            var days = hours * 24;
            var years = days * 365;
            var today = new Date();
            var todayYear = today.getFullYear();
            var todayMonth = today.getMonth()+1;
            var todayDate = today.getDate();
            var todayHour = today.getHours();
            var todayMinute = today.getMinutes();
            var todaySecond = today.getSeconds();
            /*==================================================
            Date.UTC() -- 返回date对象距世界标准时间(UTC)1970年1月1日午夜之间的毫秒数(时间戳)
            year        - 作为date对象的年份，为4位年份值
            month       - 0-11之间的整数，做为date对象的月份
            day         - 1-31之间的整数，做为date对象的天数
            hours       - 0(午夜24点)-23之间的整数，做为date对象的小时数
            minutes     - 0-59之间的整数，做为date对象的分钟数
            seconds     - 0-59之间的整数，做为date对象的秒数
            microseconds - 0-999之间的整数，做为date对象的毫秒数
            ==================================================*/
            var t1 = Date.UTC(2017, 
                              5, 
                              19, 
                              0, 
                              0, 
                              0); //北京时间
            var t2 = Date.UTC(todayYear,todayMonth,todayDate,todayHour,todayMinute,todaySecond);
            var diff = t2-t1;
            var diffYears = Math.floor(diff/years);
            var diffDays = Math.floor((diff/days)-diffYears*365);
            var diffHours = Math.floor((diff-(diffYears*365+diffDays)*days)/hours);
            var diffMinutes = Math.floor((diff-(diffYears*365+diffDays)*days-diffHours*hours)/minutes);
            var diffSeconds = Math.floor((diff-(diffYears*365+diffDays)*days-diffHours*hours-diffMinutes*minutes)/seconds);
            document.getElementById("sitetime").innerHTML="已在这里 "+diffYears+" 年 "+diffDays+" 天 "+diffHours+" 小时 "+diffMinutes+" 分钟 "+diffSeconds+" 秒";
        }
        siteTime();
    </script>



    </div>
  </footer>

  
  <div class="back-to-top" role="button" aria-label="返回顶部">
    <i class="fa fa-arrow-up fa-lg"></i>
    <span>0%</span>
  </div>
  <div class="reading-progress-bar"></div>

<noscript>
  <div class="noscript-warning">Theme NexT works best with JavaScript enabled</div>
</noscript>


  
  <script src="https://cdnjs.cloudflare.com/ajax/libs/animejs/3.2.1/anime.min.js" integrity="sha256-XL2inqUJaslATFnHdJOi9GfQ60on8Wx1C2H8DYiN1xY=" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/next-theme-pjax/0.6.0/pjax.min.js" integrity="sha256-vxLn1tSKWD4dqbMRyv940UYw4sXgMtYcK6reefzZrao=" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/fancyapps-ui/5.0.28/fancybox/fancybox.umd.js" integrity="sha256-ytMJGN3toR+a84u7g7NuHm91VIR06Q41kMWDr2pq7Zo=" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/lozad.js/1.16.0/lozad.min.js" integrity="sha256-mOFREFhqmHeQbXpK2lp4nA3qooVgACfh88fpJftLBbc=" crossorigin="anonymous"></script>
<script src="/js/comments.js"></script><script src="/js/utils.js"></script><script src="/js/motion.js"></script><script src="/js/next-boot.js"></script><script src="/js/pjax.js"></script>

  <script src="https://cdnjs.cloudflare.com/ajax/libs/hexo-generator-searchdb/1.4.1/search.js" integrity="sha256-1kfA5uHPf65M5cphT2dvymhkuyHPQp5A53EGZOnOLmc=" crossorigin="anonymous"></script>
<script src="/js/third-party/search/local-search.js"></script>




  <script src="/js/third-party/fancybox.js"></script>

  <script src="/js/third-party/pace.js"></script>


  




  

  <script class="next-config" data-name="enableMath" type="application/json">true</script><script class="next-config" data-name="mathjax" type="application/json">{"enable":true,"tags":"none","js":{"url":"https://cdnjs.cloudflare.com/ajax/libs/mathjax/3.2.2/es5/tex-mml-chtml.js","integrity":"sha256-MASABpB4tYktI2Oitl4t+78w/lyA+D7b/s9GEP0JOGI="}}</script>
<script src="/js/third-party/math/mathjax.js"></script>


 
        <div id="click-show-text"
            data-mobile = false
            data-text = 富强,民主,文明,和谐,自由,平等,公正,法制,爱国,敬业,诚信,友善
            data-fontsize = 15px
            data-random= false>
        </div>
       

      
        <script async src=https://cdn.jsdelivr.net/npm/hexo-next-mouse-effect@latest/click/showText.js></script>
      

      
    




    <script async src="/js/fancybox_param.js"></script>





<!-- APlayer本体 -->



</body>
</html>
